Cycads of Colombia.
I. Abstract II. Introduction III. Cycadales IV. Cycadaceae V. Zamiaceae VI. Phytogeography A. Choco and Montane Elements B. Rio Magdalena Valley Element C. Amazonian Element VII. Acknowledgments VIII. Literature Cited
This treatment of the Cycads of Colombia is an English-language version of the Spanish-language version that appeared in the Flora de Colombia (Stevenson, 2001). This treatment is meant to complement those of Zamia for the Guianas (Stevenson, 1991), Panama (Stevenson, 1993), and Bolivia, Ecuador, and Peru (Stevenson, 2004) and to provide one of the bases for the complete treatment of the new world cycads in Flora Neotropica. To date there has been no complete systematic treatment of the cycads of Colombia, although Sabato (1990) did provide a preliminary account. One of the important goals of the present treatment is to stimulate interest in the biology of the living cycads in Colombia and, indeed, adjacent areas of South America. Information from recent collections and fieldwork is brought together here to augment data presented on the conservation status of those species of Zamia listed by Walter and Gillett (1998) in the 1997 IUCN Red List of Threatened Plants.
CYCADALES Dumortier, Anal. Fam. P1. 65. 1829. "Cycadarieae."
A summary of the history of systematic treatments of the Cycadales can be found in Stevenson (1990a) and Norstog and Nicholls (1997). The most recent classification for the extant cycads was presented in Stevenson (1992). Sabato (1990) and Norstog and Nicholls (1997) also have the most recent treatments and discussions of Zamia for South America.
All cycad species are considered endangered and are listed in CITES appendices. In Colombia the genus Chigua D. W. Stev. is on the Appendix I list, and Zamia L. is on the Appendix II list.
As a result of the rarity of most cycad species and their commercial value in the horticultural market, many species are becoming even more threatened by removal from habitat by commercial dealers and private collectors. For this reason, no precise localities are given in this work in order to protect populations from exploitation.
Many cycad populations consist of only a few individuals, often fewer than ten or so. Therefore, it is extremely important for their conservation that herbarium specimens consist only of leaves and/or cones but not stems. Cycads rarely branch and have no axillary buds, so that removal of the stem tip results in death of the plant. Stem features such as diameter, height, cataphyll size, and shape can be recorded in field notes and incorporated into labels. Only leaves are needed for identification. These may be supplemented by cones, but stems are not needed. The most serious threat, though innocent, to a population can be the overcollection of plants for the herbarium.
Cycads are also threatened by habitat destruction and/or removal of the pollinators (see discussion under Zamia). One proposal for their continued viability as populations is to begin to establish nurseries to raise plants from wild collected seed. Because nearly 75% of the seeds fail to become established as plants, the removal of ovulate cones for seed harvest will have a minimal impact on the population. The nursery-grown seedlings and young plants then can be marketed to generate local revenue. This revenue will be continual, for the demand for exotic cycads continues to increase.
Key to the families of the Cycadales in Colombia 1. Pinnae with a single prominent primary vein and no lateral veins; microsporophylls acuminate at apex, megasporophylls not organized into a strobilus, leaflike, bearing 2-10 marginal ovules in the proximal part; seeds flattened (platyspermic) Cycadaceae 1. Pinnae with dichotomously branched lateral veins (appearing parallel); microsporophylls acute to peltate at apex, megasporophylls organized into a strobilus, peltate, bearing two ovules under the apical part; seeds radial (radiospermic), not flattened Zamiaceae
CYCADACEAE Persoon, Syn. pl. 2: 630. 1807. "Cycadeae," nom. cons. TYPE GENUS: Cycas L.
Stems columnar, sparingly branched, pachycaulous, from 0.5 to 7 m, clothed with persistent leaf bases in the upper region and with infrequent adventitious bulbils. Leaves pinnately compound, 1-3 m long, borne in a terminal crown of a few to more than 50; petiole with two rows of lateral spines representing reduced pinnae; pinnae in opposite to subopposite pairs, each pinna with a conspicuous, thick primary vein and no secondary veins. Plants strictly dioecious. Pollen strobili borne terminally and composed of numerous closely imbricate, flat, acuminate microsporophylls with pollen-bearing structures on the lower surface. Megasporophylls not organized into a determinate strobilus but, rather, spirally arranged in a loose terminal cluster and falling separately at maturity, with the central axis eventually continuing vegetative growth; each megasporophyll with a proximal stalked portion bearing 2-10 marginally inserted ovules and a distal pinnatifid, pectinate, or toothed laminar portion. Seed coat consisting of an outer fleshy portion and an inner stony layer, large, brown to red or orange/red at maturity and, generally, distinctly flattened.
Distribution: One genus, Cycas, with perhaps 100 species confined to the Old World Tropics. The two species treated here are commonly planted as ornamentals in New World subtropical and tropical areas and are apparently becoming somewhat naturalized in human-made disturbed habitats (e.g., abandoned home sites).
Uses: The stems and seeds of Cycas spp. are used as a source of starch for breads and puddings after thorough washing to remove toxic and carcinogenic compounds. They are often called "sago palms," particularly C. revoluta.
CYCAS L., Sp. Pl.2: 1188. 1753.
LECTOTYPE: C. circinalis L.; designated by Stevenson in Jarvis et al. (1993).
Characters the same as for the family.
Key to the species of Cycas in Colombia 1. Pinnae 9-14 mm wide, with flat or scarcely revolute margins; sterile part of megasporophylls serrate; microsporophylls long-acuminate 1. C. rumphii 1. Pinnae less than 7 mm wide, with revolute margins; sterile part of megasporophylls pinnatifid; microsporophylls abruptly acuminate 2. C. revoluta
1. CYCAS RUMPHII Miq., Bull. Sci. Phys. Nat. Neerl. 1839: 45. 1839.
TYPE: LECTOTYPE: the illustration: Rumphius 1741: tab. 23. (fide Hill, 1994).
Cycas celebica Miq., Bull. Sci. Phys. Nat. Neerl. 1839: 45. 1839. TYPE: the illustrations: Rumphius 1741 : t. 20, 21.
Cycas rumphii var. timorensis Miq., Comm. Phytolog.: 125-126. 840-1841. TYPE: INDONESIA. Timor: ex Herb. Mus. Paris (HOLOTYPE: L; ISOTYPES: LE, U).
Stems arborescent, 2-5(10) m tall. Leaves 1-3 m long, pinnae 10-30 cm long. Pollen strobili 60-70 cm long, 15-18 cm diam.; microsporophylls with 500-900 microsporangia. Megasporophylls 15-25 in a crown and with 6-8 ovules each. Seeds yellow to brown, the stony layer with sharp pointed apex and two lateral median ridges extending toward the base.
Natural distribution." Malaya, Sri Lanka, southern India, the Philippines, and Indonesia. Introduced as an ornamental.
Eponymy: The specific epithet is for Georg Rumphius, who first illustrated and described the species as Olus calappoides (Rumphius, 1741).
Notes: When Linneaus originally described the genus Cycas he included only a single species, C. circinalis L. There is no specimen in the Linnean Herbarium. However, Linneaus made reference to eight earlier works, four of which contained illustrations that can serve as the lectotype of C. circinalis. Because of the polymorphic nature of these illustrations, subsequent authors used most of them as types of segregate species but without typifying C. circinalis. As a result of typification of C. circinalis by Stevenson in Jarvis et al. (1993) and of C. rumphii by Hill (1994), it is clear that most if not all specimens in cultivation labeled C. circinalis are in fact C. rumphii.
Specimens examined: COLOMBIA. Tolima: Municipio de Mariquita, "Mi Ranchito," J. Santa & L. Escobar 849 (HUA, NY).
2. CYCAS REVOLUTA Thunb., Verh. Holl. Maatsch. Weetensch. Haarlem 20: 424. 1782. TYPE: JAPAN, ex herb Thunberg s.n. (HOLOTYPE: UPS-23734).
Cycas revoluta vat. brevifrons Miq., Tijdschr. Wis-Natuurk. Wetensch. Eerste Kl. Kon. Ned. Inst. Wetensch. 1: 207. 1848. TYPE: (?).
Cycas revoluta var. planifolia Miq., Monogr. Cycad.: 25-26. 1842. TYPE: Hort. Amsterdam, 1840, Miquel s.n. (HOLOYPE: U).
Cycas revoluta var. prolifera Siebold & Zucc., Abh. Math.-Physik. Cl. Konigl. Bayer. Akad. Wiss. 14(3): 236. 1846. TYPE: from garden material (?).
Stem arborescent, 1-3(7) m tall, often with numerous small bulbils on trunk. Leaves 0.5-2 m long, pinnae 6-18 cm long. Pollen strobili 40-50 cm long, 8-12 cm diam.; microsporophylls with 200-450 microsporangia. Megasporophylls 40-200 in a crown and with (2)4(6) ovules each. Seeds orange to red, the stony layer without ridges and occasionally with a very small apical point.
Natural distribution: Southern Japan and eastern China. Introduced as an ornamental. Etymology: In reference to the abaxially rolled (revolute) leaflet margins.
Specimen examined: COLOMBIA. Tolima: Hacienda "El Santano," C. Barbosa 1726 (FMB).
ZAMIACEAE Reichenbach, Handb. nat. Pfl.-Syst. 139. 1837.
TYPE GENUS: Zamia L.
Stem subterranean to arborescent, when arborescent smooth or clothed in persistent leaf bases. Ageotropic coralloid roots containing nitrogen-fixing endophytic cyanobacteria present near the soil surface. Leaves with or without small stipules, paripinnately compound, in a crown of few (1-15) to many (30); petiole and lower third of rachis smooth or with small prickles or with reduced spinose pinnae; pinnae 10-120 in subopposite to opposite pairs, articulated with rachis, densely pubescent when young, glabrous when mature, venation dichotomous, with or without a midrib. Plants' dioecious. Strobili one to several, usually emerging from center of crown; sporophylls fiat to peltate. Pollen strobili of numerous microsporophylls with sporangia located on the abaxial surface and rarely on the adaxial surface; microsporangia many, in groups of 2-5 and dehiscing by longitudinal slits; pollen monosulcate, proximal sculpturing psilate to foveolate. Ovulate strobili of numerous ovule-bearing, stalked megasporophylls, each with two ovules. Seed coat when mature consisting of a red or orange/red or white outer fleshy layer and an inner stony layer; megagametophyte farineacous; embryo with two cotyledons and a coiled suspensor.
Distribution: About 180 species in eight genera, in tropical to warm temperate regions of Africa, Australia, the West Indies, and North, South, and Central America. About 80 species in five genera occur in the Neotropics (Osborne et al., 1999): Microcycas A. DC. (monotypic) is endemic to Cuba; Ceratozamia Brongr. (12 species) is centered in Mexico, with one species occurring in Belize and two species in Guatemala; Dioon Lindley (10 species) is primarily found in Mexico, with one species endemic to Honduras and Nicaragua; Chigua (2 species) is endemic to Colombia; and Zamia L. (approximately 50 species) is widespread, ranging from Georgia, U.S.A., to Bolivia, with 16 species in Colombia. Seven species of Zamia are endemic to Colombia.
Key to the genera of Zamiaceae in Colombia 1. Leaflet venation with a prominent midrib and lateral dichotomies Chigua 1. Leaflet venation strictly dichotomous Zamia
CHIGUA D. Stev., Mere. New York Bot. Gard. 57: 170. Fig. 1. 1990. (Fig. 1).
[FIGURE 1 OMITTED]
TYPE SPECIES: Chigua restrepoi D. Stev.
Stem hypogeous, ellipsoid, to 10 cm diam. Cataphylls pubescent, triangular, stipulate. Leaves 2-5, paripinnate, glabrous, stipulate; petiole subterete, with numerous small prickles; rachis semiterete, small prickles present proximally, smooth distally. Leaflets alternate proximally, subopposite medially, opposite distally, papyraceous, sessile, and articulate with rachis, cuneate at base, caudate at apex, prominent midvein present, lateral veins longitudinal and dichotomously branched, margins with well-defined teeth, glabrous. Pollen strobili cylindrical, covered with reddish brown tomentum; peduncle glabrous. Microsporophylls subpeltate, sterile tip hexagonal. Ovulate strobili cylindrical, covered with reddish brown tomentum; peduncle glabrous. Megasporophylls peltate with a narrow basal stalk, sterile tip hexagonal with a conspicuous bump at each angle of the hexagon. Seeds ovoid, red at maturity.
Distinguishing features: Although Chigua leaflets have a midrib, as do also those of Cycas and Stangeria T. Moore, the anatomy and branching pattern of this midrib is distinctively different from those in Cycas and Stangeria (Stevenson et al., 1996). Stevenson (1990a, 1990b, 1992) considers Chigua most closely related to Zamia, based upon both biogeography and cladistic analyses. In fact, it may be discovered that Chigua is nested within Zamia when a species-level phylogenetic analysis of the New World cycads is performed. This prediction is supported for now by phytochemical evidence because Zamia and Chigua have the same composition and distribution of monosaccharides in their mucilage, whereas each of the other cycad genera has its own unique pattern of mucilage monosaccharides (Stevenson & Siniscalco Gigliano, 1989).
Distribution: Two species only known from their type localities in northern Colombia (Fig. 2), where the genus occurs in primary rain forest at 100-200 m. The number and size of the populations of both species are unknown. The area itself is under threat of habitat destruction from cattle grazing, mining activities, and oil exploration. There is a high demand for plants of Chigua in the horticultural market, and nursery-grown plants from seed would provide a lucrative and constantly expanding market of renewable resources.
[FIGURE 2 OMITTED]
Chigua was first collected as an unicate by Francis Pennell in 1918. It was not until 1986 that a population conforming to Pennell's collection was re-located by Rodrigo Bernal.
Conservation status': CITES Appendix I: Considered Critically Endangered.
Etymology: The generic name is derived from the name used for cycads by indigenous people in the Choco, Colombia.
Key to the species of Chigua in Colombia 1. Median leaflets lanceolate 1. C. restrepoi 1. Median leaflets linear to linear-lanceolate 2. C. bernalii
1. CHIGUA RESTREPOI D. Stev. (Fig. 1A-G), Mem. New York Bot. Gard. 57: 170. 1990. (Fig. 1A-H).
TYPE: COLOMBIA. 14 Mar 1987, D. Stevenson 693 (HOLOTYPE: HUA; ISOTYPES: FTG, NY).
Leaves' 2-3, glabrous, stipulate; petiole subterete, 60-80 cm long, armed with prickles; rachis semiterete, 60-100 cm long, armed with prickles below, smooth above. Leaflets alternate below, subopposite in middle, opposite above, 20-30 on each side, lanceolate, 3-5 cm wide, 15-25 cm long, papyraceous, sessile, cuneate at base, caudate at apex, margins with well-defined teeth. Pollen strobili cylindrical, 5 cm long, 2 cm diam., covered with reddish brown tomentum; peduncle glabrous, 10 cm long, 1 cm diam.; microsporophylls peltate, sterile peltate tip fiat. Ovulate strobili cylindrical, 15 cm long, 5 cm diam., covered with reddish brown tomentum; peduncle glabrous, 30 cm long, 1.5 cm diam.; megasporophylls peltate, with a narrow basal stalk, hexagonal with a conspicuous bump at each angle of the hexagon. Seeds ovoid, red at maturity. 2n = 18 (Caputo et al., 1996).
Etymology: The specific epithet is in honor of Padre Sergio Restrepo, who re-located the species, accompanied and guided Knut Norstog and Dennis Stevenson during their fieldwork, and was subsequently martyred (see Stevenson, 1990c: vii).
Specimens examined: COLOMBIA. Primary rain forest, 120 m, 24 Jul 1986, R. Bernal, G. Galeano & D. Restrepo 1138 (COL, FTG); 28 Sep 1986, I. Turner 3 (FTG); 90-1:20 m, 5-6 Mar 1918, F. Pennell 4608 (NY).
2. CHIGUA BERNALII D. Stev. (Fig. 1H), Mem. New York Bot. Gard. 57: 170. 1990. (Fig. 1I).
TYPE: COLOMBIA. Primary rain forest, 150 m, 27 Jul 1986, R. Bernal, G. Galeano & D. Restrepo 1189 (HOLOTYPE: COL; ISOTYPE: FTG).
Leaves 2-3, glabrous, stipulate; petiole subterete, 1-1.4 m long, armed with prickles; rachis semiterete, 60-160 cm long, armed with prickles below, smooth above. Leaflets alternate below, subopposite in middle, opposite above, 30-50 on each side, linear to linear-lanceolate, 1-1.5 cm wide, 30-35 cm long, papyraceous, sessile, cuneate at base, caudate at apex, margins undulate with well-defined teeth. Strobili unknown.
Etymology: The specific epithet is for Rodrigo Bernal, who first discovered and collected the species.
ZAMIA L., Sp. P1. ed. 2: 1659. 1763, nom. cons.
TYPE SPECIES: Zamia pumila L.
Palma-Filix Adanson, Faro. Pl. 2: 21, 587. 1763.
Aulacophyllum Regel, Gartenflora 25:140. 1876.
Stems subterranean and tuberous or trunk to 5 m, 3-25 cm diam., often dichotomously branched, wrinkled to smooth, with or without persistent leaf bases. Cataphylls alternating with leaf flushes, 1-6 cm long, sheathing at first, with a pair of inconspicuous stipules. Leaves generally few (2-15), paripinnate. Petioles with stipules, smooth or armed with scattered prickles. Rachis bearing 5-60 pairs of opposite to subopposite leaflets, smooth or armed with scattered prickles in lower one-third two-thirds, ending in a terminal acute spine. Leaflets linear to oblong to broadly ovate, 8-45 cm long and 1-15 cm wide, sessile to petiolulate, with or without a collar-shaped gland, rounded to long-acuminate apically, margin entire or more commonly serrate in upper half. Pollen strobili pedunculate, cream colored to tan to dark reddish brown, 1-30, emerging from center of leaf crown, cylindrical but gradually tapering toward acute apex, each 1-30 cm long and 0.5-8 cm diam., densely pubescent; microsporophylls obscurely peltate, 0.5-1 [0.2-1.5] cm long, 8-64 abaxial microsporangia (rarely a few adaxially) in 2-4 clusters; pollen exine foveolate. Ovulate strobili pedunculate, tomentose, green to dark reddish brown, usually solitary but occasionally up to 3, emerging from center of leaf crown, cylindrical to slightly ovoid with blunt or slightly acute apex, each 6-55 cm long and 3-20 cm diam., densely pubescent or glabrous; megasporophylls arranged in 5-21 vertical orthostichies, the exposed tips thick, truncate, hexagonal, with six lateral facets surrounding a central prominent, often depressed facet, each bearing two lateral ovules. Seeds with a red to orange-red or white sarcotesta and a stony endotesta, ovoid, 1-4 cm long. Chromosome numbers 2n = 16, 18-28.
Distribution and habitat: A genus of about 55 species represented sporadically throughout the Neotropics, but some species native to the subtropics (e.g., Georgia, U.S.A., and Bolivia); most species are narrow endemics, although a few are more widespread. The plants generally grow in undisturbed primary forest at elevations from sea level (e.g., Zamia roezlii Linden) to 2700 m (e.g., Z montana A. Br.). Zamia is the most ecologically, morphologically, and karyologically diverse of the cycad genera. Most species grow in dry soils. When they occur in wet areas, they are usually on well-drained sites or rocky slopes. However, there are exceptions, such as the epiphytic Z. pseudoparasitica Yates in Panama and the salt-tolerant Z. roezlii, which can grow in mangrove swamps on the Pacific coast of Colombia. One also finds some species in the Amazonian rain forest, but usually on the sides of small, rocky mountains, where the plants appear to do well, in contrast to their paucity in the wet understory. In general, species such as Z obliqua A. Br., which tolerate wet habitats, have well-developed trunks. All species have ageotropic coralloid roots that contain nitrogen-fixing cyanobacteria (blue-green algae). The greatest development of these coralloid roots appears in the epiphytic Z. pseudoparasitica, in which the root masses are hemispherical and up to 25 cm diam. Because the cyanobacteria grow best under alkaline conditions and the cycads appear to require them as a nitrogen source, the cycads do best and show the greatest species diversity on alkaline to neutral soils. Populations of Zamia in the Neotropics that grow in lowland acid conditions generally consist of a very few, widely spaced depauperate plants that cone infrequently. The healthier populations of such species seem to be restricted to drier soils and to the slopes of hills and small mountains of 1500 m.
Some species of Zamia that occur in Colombia have their northern limits of distribution in Panama. For example, Z. manicata Linden ex Regel and Z. obliqua extend from the Choco of Colombia into the Darien of Panama (Stevenson, 1993). Zamia chigua Seemann is known from the Choco of Colombia and then is disjunct to the Chiriqui area of Panama (Stevenson, 1993). Seven of the 16 species of Zamia found in Colombia are endemic to that nation: Z. amplifolia Masters, Z. disodon D. Stev. & Sabato, Z encephalartoides D. Stev., Z. hymenophyllidia D. Stev., Z melanorrhachis D. Stev., Z montana A. Br., and Z wallisii A. Br.
Conservation status: All species of Zamia are listed in CITES Appendix II. Details on conservation and the 1997 IUCN Red List status (Walter & Gillett, 1998) are given for each species treated herein.
Vegetative morphology: The general growth habit in Zamia ranges from species with small, smooth, subterranean stems (e.g., Z. melanorrhachis) to species with tall, columnar stems of up to 5 m (e.g., Z. obliqua, Z roezlii, or Zamia amplifolia). These may be either smooth and slender (10-12 cm), as in Z. obliqua, or have subpersistent leaf bases and considerable thickness (up to 25 cm), as in Z roezlii. In species without aerial trunks, the stems remain underground as a result of taproot and stem contraction (Stevenson, 1980a). Because axillary buds are not present in the cycads, branching is uncommon. Three types of vegetative branching do occur: apical dichotomies, adventitious buds formed from leaf-base callus, and adventitious buds formed from lateral meristems originating near points of injury (Stevenson, 1988). The amount of secondary wood is generally a small part of the stem, which is composed mainly of a large parenchymatous pith and a broad cortex derived from a primary thickening meristem (Stevenson, 1980b). Consequently, species of Zamia are pachycaulous, as are all cycads. Unlike some genera, such as Cycas, polyxylic secondary growth does not occur in Zamia (Stevenson, 1990a).
Leaf morphology and production are variable in Zamia. The only feature of leaf morphology that is correlated with stem habit is the shape (ptyxis) of the emerging leaves. In general, species with subterranean axes, such as Z. lecointei Ducke, have inflexed ptyxis, in contrast to species with well-developed trunks, such as Z. obliqua, which have erect ptyxis (Stevenson, 1981). All species of Zamia produce one annual flush of leaves that may contain 1-0 or more leaves. The production of a single annual leaf appears to be limited to a few, but not all, species with subterranean stems (e.g., Z. wallisii). The leaflets are articulated with the rachis. Venation is open and dichotomous. Leaflets of some species have entire margins (e.g., Z. encephalartoides), while in others the leaflets have distinct marginal teeth (e.g., Z. obliqua). The teeth may be inconspicuous and restricted to the apical region, as in Z. lecointei, or may be well developed and occur all along the leaflet margins, as in Z poeppigiana Martius & Eichler. In the cycads, biserrate leaflets are found only in Z. disodon D. Stev. Leaflet texture varies from extremely coriaceous (Z encephalartoides) to membranaceous (Z. disodon and Z. hymenophyllidia). Most species of Zamia have flat, smooth leaflets. However, a few species, such as Z. roezlii and Z wallisii, have leaflets that are deeply grooved adaxially between the veins. This character, along with supposed sequential versus simultaneous leaf production in these species, was used to segregate the genus Aulacophyllum Regel (1876). However, leaf production in these species was not directly observed by Regel and, in fact, sequential leaf production does not occur in any neotropical cycad. Moreover, the presence of deeply grooved leaflets is not correlated with any other characters, and not all species of Zamia included by Regel in Aulacophyllum have strongly nerved leaflets. Also, the species of Zamia that do have deeply grooved leaflets that were included in Aulacophyllum by Regel (1876) do not form a clade (Caputo et al., 1996).
In general, the leaflets are sessile, but some species have a distinct petiolule (e.g., Zamia wallisii and Z. manicata). In fact, the latter species is very unusual in the Cycadales, because there is an conspicuous abaxial, semicircular, gland-like structure at junction of the lamina and the petiolule. The function and structure of this gland-like structure remain enigmatic (Stevenson, 1990a).
Reproductive morphology: As in all eycads, the species of Zamia are dioecious. Compared with the variability found in vegetative morphology, strobilus morphology is more constant, with much variation accounted for in the size and color of strobili and in the shape of the terminal portions of the sporophylls. Strobilus color varies, from black in West Indian species, Z angustifolia Jacquin, to tan in many species, to yellow-tan in Z. obliqua, to dark red-brown in Z. manicata, to green in ovulate strobili of Z. encephalartoides. Generally, microsporangiate and ovulate strobili are the same color within a species. However, there are exceptions, such as Z. encephalartoides, which has tan microsporangiate strobili and green ovulate strobili.
Microsporangiate strobili vary in size, from 1-3 cm long when mature in Zamia melanorrhachis D. Stev. and Z hymenophyllidia D. Stev. to 30 cm long in Z. roezlii. Also, the peduncles of the microsporangiate strobili of Z. melanorrhachis and Z. hymenophyllidia are unusual in being very slender, 2-4 mm diam., and very long, up to 30 cm. Ovulate strobili vary in length, from 2.5 cm when mature in the Cuban endemic Z pygmaea Sims, to more than 50 cm long in Z. poeppigiana. All sporophylls are peltate, with the expanded tip composed of a terminal facet surrounded by six inclined facets. In most species, the six facets surrounding the terminal facet are only slightly inclined. In other species, such as Z. obliqua and Z encephalartoides, the tip appears very distinctly pyramidal because the six surrounding facets are steeply inclined and the terminal facet is smaller than the lateral facets. This is particularly apparent in the microsporophylls.
Generally in cycads, pollen-bearing microsporangia are found only on the abaxial surface of the microsporophylls. However, in at least five species of Zamia, including Z. obliqua, Z. melanorrhachis, Z hymenophyllidia, and Z encephalartoides, both adaxial and abaxial microsporangia are present. These abaxial microsporangia are few and located only in one or two rows adjacent to the sterile tip. In the species that have been examined, the pollen of Zamia is foveolate (Audran & Masure, 1977; Dehgan & Dehgan, 1988; Marshall et al., 1989).
Cytology; Cycad genera are remarkably uniform cytologically, with the exception of Zamia (Moretti, 1990a, 1990b). All North American and West Indian plants that have been examined are 2n = 16 (Norstog, 1980; Moretti, 1990a). In striking contrast, the diploid number in Central and South American species is quite variable between and within species (Moretti, 1990a, 1990b; Norstog, 1980, 1981). Diploid numbers are also variable within a population (Norstog, 1980, 1981; Moretti & Sabato, 1984; Moretti, 1990a, 1990b; Moretti et al., 1991, 1993). Even more remarkable, all plants of some populations of Z. paucijuga Wieland (e.g., on Maria Cleof Island, Mexico 2n = 27) appear to have an odd diploid number (Moretti & Sabato, 1984; Moretti, 1990a, 1990b), even though these populations do not contain apomictic plants and consist of seedlings and plants of varying age (i.e., presumably the populations are sexually reproductive). Variation in diploid chromosome number within and among populations of a species can be better understood from the relative difference in the number of metacentric versus the number of telocentric chromosomes. For example, in Z. paucijuga there is a series of karyotypes of 2n = 23, 24, 25, 26, 27, and 28. All of these karyotypes have two submetacentric and two acrocentric chromosomes and differ only in the number of metacentric (M) and telocentric (T) chromosomes. For example, in the 2n = 23 karyotype there are 5 M and 14 T chromosomes, whereas the 2n = 24 karyotype has 4 M and 16 T. For each increase in the diploid number there is a corresponding decrease of one metacentric chromosome and a corresponding increase of two telocentric chromosomes. This has been interpreted as Robertsonian fusion of two telocentrics to form one corresponding metacentric (Norstog, 1980) and as Robertsonian fission of each metacentric to form two corresponding telocentrics (Moretti, 1990a, 1990b). Regardless of the interpretation, fusion or fission, therein lies the explanation of populations composed of individuals of differing diploid numbers.
Pollination biology: Insect pollination in the cycads was first unequivocally demonstrated in the Mexican species, Zamia furfuracea L. fil. in Aiton (Norstog et al., 1986) and has since been demonstrated for Z. integrifolia in Florida by Tang (1987a). In both cases, pollination is by curculionid (snout) weevils of the genus Rhopalotria and by a clavicorn beetle, Pharaxonotha zamiae. Different species of Rhopalotria are associated with these two species of Zamia; viz., R. mollis is a pollinator of Z. furfuracea, and R. slossoni is a pollinator of Z. integrifolia. Recently, Fawcett, Norstog, and Stevenson (unpub. obs.) have also found R. slossoni associated with Z. integrifolia on New Providence Island, Bahamas. Other species of Zamia may be pollinated by snout weevils and clavicorn beetles as well, and R. bicolor and Pharaxonotha sp. have been found in pollen cones of Ceratozamia and Dioon (Vovides, 1991). Rhopalotria dimidata appears to be associated with Z. pygmaea in Cuba, and an unidentified species of Rhopalotria is associated with Z. inermis in Mexico (Vovides, pers. com.) and with Z. loddigesii Miq., Z. fairchildiana, Z. encephalartoides, and Z. muricata Willd. in Mexico, Panama, Colombia, and Venezuela, respectively (Fawcett, Norstog, and Stevenson, unpub, obs.). Further studies by Norstog and Fawcett (1989) demonstrated that R. mollis and Z. furfuracea are symbiotic. They have shown that breeding, larval stages, and pupation in this snout weevil occur during pollen-cone development. Moreover, some of the pupae undergo the diapause phase and emerge as adults when the pollen cones of the next season develop. The adult weevils copulate and oviposit on the pollen cones, and the resulting larvae complete their cycle in the cones, with some larvae going into diapause. The case of P. zamiae is less obligate, and these beetles, beside being less effective pollinators, are also able to utilize other food sources, particularly palm pollen.
Tang (1987a) demonstrated effective pollination in Zamia integrifolia by Rhopalotria mollis, a snout weevil, and Pharaxonotha zamiae, a clavicom beetle. Tang (1987b, 1993) also showed that pollen and seed cones have a daily thermogenic cycle during elongation, when the pollen is shed, and at the time of pollination. The thermogenic cycle is correlated with odor production in these cones. In some instances the fragrances appear to be similar or the same as those produced by some angiosperms (Pellmyr et al., 1991). These odors seem to attract snout weevils to Zamia cones and possibly to play a role in releasing larvae from diapause. Rhopalotria larvae collected and stored while in diapause were observed to be released from diapause when maturing pollen cones were brought into the laboratory (Fawcett, pers. com.) Further studies by Fawcett and Norstog (1993) demonstrated that, as in the Z. furfuracea--R, mollis symbiosis, there is also a Z. integrifolia--R, slossoni symbiosis. The case with Pharaxonotha zamiae remains enigmatic, because this beetle spends time on other plants, is more general in its food selection, has its diapause period in the soil, and apparently does not copulate on pollen cones of Z. integrifolia. In both Zamia species snout weevils and clavicom beetles do not interfere with each other, because they have a tendency to occupy and utilize different regions of the pollen cone and have slightly different timing in their life cycles (Norstog & Fawcett, 1989; Fawcett & Norstog, 1993; Fawcett et al., 1995). Rhopalotria slossoni prefers sporophylls at the base of the pollen cone, whereas P zamiae prefers sporophylls at the top of the pollen cone (Fawcett & Norstog, 1993). Also, Pharaxonotha lays its eggs some time after Rhopalotria oviposits, so that the larvae of the weevil start to pupate when the larvae of the beetle are young. One of the more interesting observations about insect pollination in Zamia is that in northern Florida Rhopalotria is absent (although there are historical records of its presence), and pollination is effected by Pharaxonotha alone. This led Fawcett and Norstog (1993) to conclude that Rhopalotria has become extinct in this area, which may have important consequences for reproduction in populations of Zamia in northern Florida.
These observations, combined with the facts that the cycads have a fossil record extending back to the Early Permian (Gao & Thomas, 1989), that the Curculionoidae are primitive beetles with a fossil record beginning in the Carboniferous, and that these weevils are also associated with Mesozoic Bennettitales (Crepet, 1979), suggest that insect pollination was well developed before the arrival of the angiosperms. It would appear that these insect pollinators have coevolved with cycads (Crowson, 1991; Oberprieler, 1995a, 1995b), a conclusion supported by phytochemical evidence because all parts of the cycad plant, except the mature fleshy seed coat, contain highly toxic compounds. Perhaps the most interesting toxic compound in cycads is the neurotoxin and nonprotein amino acid 2-amino-(methylamino)propanoic acid (BMAA). Present in the tissues upon which the larvae feed, BMAA would be incorporated into proteins, causing tertiary protein configuration to be disrupted or changed in such a way that the insects fail to pupate or metamorphose normally. Thus, these insects have found a way either to sequester BMAA or to detoxify it, because no such failure to pupate occurs in the snout weevils or clavicorn beetles that feed on cycads as larvae. There is good evidence that the BMAA-containing cells in the microsporangiate cones lack primary pit fields and that the BMAA is not released. These cells are ingested whole by the weevil larvae and then excreted and incorporated into cocoon cases of the diapause larvae (Vovides et al, 1993; Stevenson et al., 1998). Furthermore, because different weevil species are associated with different cycad species, at least some weevils have coevolved with cycads at the species level.
Note: Information concerning the typification of names in Zamia can be found in Stevenson and Sabato (1986).
Key to the species of Zamia in Colombia 1. Leaflets deeply grooved above between veins, appearing plicate 2. Leaflets toothed at least in upper third, petiolulate; stems subterranean 16. Z. wallisii 2. Leaflets entire, sessile; plants arborescent 3. Leaflets linear, falcate basally 14. Z. roezlii 3. Leaflets elliptic or obovate 4. Leaflets obovate 10. Z. montana 4. Leaflets elliptic 2. Z. amplifolia 1. Leaflets smooth to striate, not appearing plicate 5. Leaflets with a distinct petiolule and a gland-like collar at the base of the lamina 8. Z. manicata 5. Leaflets sessile and without a gland-like collar 6. Leaflets entire or with a few minute teeth apically 7. Petioles smooth; leaflets strongly coriaceous, margins revolute 5. Z. encephalartoides 7. Petioles with prickles 8. Petiole sparsely prickled, rachis without prickles, prickles never branched 9. Leaflets membranous 6. Z. hymenophyllidia 9. Leaflets papyraceous to coriaceous 7. Z. lecointei 8. Petiole and rachis densely prickled, prickles often branched 10. Leaflets imbricate, lanceolate, 40-80 pairs; petiole glabrous 3. Z. chigua 10. Leaflets nonimbricate, oblong-lanceolate, 10-30 pairs; petiole ferruginous 1. Z. amazonum 6. Leaflets obviously toothed 11. Leaflets elliptic to oblong-elliptic 12. Leaflets membranous, coarsely toothed, and at least some biserrate 4. Z. disodon 12. Leaflets papyraceous, finely serrulate 13. Leaflets elliptic, falcate, 10-20 pairs; plants arborescent 12. Z. obliqua 13. Leaflets oblong- elliptic, symmetrical, 3-6 pairs, stems subterranean 15. Z. ulei 11. Leaflets oblong-lanceolate to linear-lanceolate 14. Leaflets long, linear-lanceolate, falcate basally, marginal teeth aculeate and nearly at right angles; plants arborescent 13. Z. poeppigiana 14. Leaflets oblong- lanceolate, cuneate basally, marginal teeth serrate and at an acute angle; stems subterranean 15. Leaflet pairs 4-10, upwardly falcate; petioles dark purple to brown, prickles minute 9. Z. melanorrhachis 15. Leaflet pairs 15-35, symmetrical; petioles green, prickles conspicuous 11. Z. muricata
1. ZAMIA AMAZONUM D. W. Stevenson, Flora de Colombia 21:33 & Fig. 3. 2001. (Fig. 3).
[FIGURE 3 OMITTED]
TYPE: BRAZIL. Amazonas: Confluence of Rio Tauri and Rio Icana, D. Stevenson 886 (HOLOTYPE: INPA; ISOTYPES: COL, MO, NY, U).
Stem subterranean, 3-8 cm diam. Cataphylls triangular basally, linear-lanceolate apically, 3-8 cm long, 1-2 cm wide. Leaves 2-6, 0.5-2.5 m long, oval to elliptic; petiole 0.5-1 m long, often ferruginuous, armed with small to stout branched prickles; rachis 0.5-1 m long, with 10-30 subopposite pairs of leaflets, armed with prickles in the lower third. Leaflets chartaceous to papyraceous, oblong-lanceolate to lanceolate, acuminate at apex, denticulate in upper half, 15-20 cm long, 2-4 cm wide. Pollen strobili 2-6, cylindrical, brown, 6-10 cm long, 1-2 cm diam.; peduncle 8-15 cm long. Ovulate strobili usually solitary, dark red-brown, 10-15 cm long, 3-5 cm diam.; peduncle 5-8 cm long. Seeds with a red outer fleshy layer, ovoid, 1 cm long, 0.5 cm diam.
Distinguishing features: Zamia amazonum is a variable species that most closely resembles Z. lecointei and Z. muricata. However, it can be distinguished from these two species on the bases of the rachis being densely tomentose when young and being densely prickled with the prickles often branched. The seed cone is smaller, being less than 15 cm including the peduncle than the seed cones of Z. lecointei and Z. muricata, which are more than 15 cm long.
Distribution: A widespread species found in Amazonian areas of Brazil, Colombia, Peru, and Venezuela and disjunct in the Choco of Colombia (Fig. 2).
Conservation status: Fairly common locally throughout its range. Not yet listed in the IUCN Red List of Threatened Plants, but the status throughout its range would be R,II,R.
Etymology: The specific epithet refers to the wide distribution of this species throughout the upper Amazon Basin.
Specimens examined: COLOMBIA. Amazonas: Rio Caqueta, Galeano et al. 2076 (COL, NY), E. Ligia & B. Urrego 662 (Herbario Amazonico, NY); Tarapaca, R. Bernal et al. 2035, 2076 (COL, NY); Puerto Buenaventura, C. Sastre 3483 (COL); La Pedrera, R. Cortes 493 (COL). Choco: Quibdo, R. Bernal et al. 1090 (COL); Rio Mecana, A. Juncosa 1721 (MO, NY), J. W. Kress & B. Echeverry 89-2571(SEL, US). Vaupes: R. Bernal et al. 1218 (COL); Rio Priaparana, R. Schultes & I. Cabrera 17345 (F, GH).
2. ZAMIA AMPLIFOLIA Masters, Gard. Chron. 10: 810. 1878.
TYPE: COLOMBIA. Valle: Kiem & Norstog 30 (NEOTYPE: FTG 3 sheets; fide Stevenson & Sabato, 1986).
Stem arborescent, to 2.5 m tall. Cataphylls triangular basally, lanceolate apically, 2-3 cm long, 1-2 cm wide. Leaves 3-6, 1-2 m long; petiole 0.5-1 m long, sparsely to densley prickled; rachis with 6-10 pairs of leaflets, occasionally with a few prickles in the lower third. Leaflets elliptic, grooved between the veins on the adaxial surface, cuneate basally, acuminate apically, margins entire, the median ones 30-50 cm long, 12-15 cm wide. Pollen strobili cream to tan, cylindrical to elongate-cylindrical, 8-12 cm long, 1-2 cm diam. Ovulate strobili brown, short pedunculate, cylindrical to ovoid cylindrical, 20-40 (50) cm long, 8-12 cm diam. Seeds red, ovoid, 1.5-2.5 cm diam. 2n = 18 (Norstog, 1980).
Distinguishing features: Zamia amplifolia has been collected only four times in the past 120 years and then only as vegetative material. Norstog and Nicholls (1997) considered Z. amplifolia to be very similar to Z. dressleri D. Stev., a species described from central Panama (Stevenson, 1993). However, Z. amplifolia has well-developed trunks and entire margined leaflets, whereas Z. dressleri has a subterranean stem and obviously toothed leaflet margins. Zamia amplifolia actually seems more similar in stature to Z. skinneri A. Dietrich and differs from it only in having entire leaflet margins as opposed to the coarsely toothed leaflet margins of Z. skinneri. The lack of reproductive material of Z. amplifolia leaves this relationship ambiguous, but it is interesting to note that other species from the Choco, such as Z. obliqua and Z. chigua, have disjunct populations in central and southern Panama.
Distribution: Endemic. Known from only three collections (Fig. 2), all near the neotype locality.
Conservation status: This species is so rarely collected that it is difficult to assess. However, this leads one to think that it is very rare. The existing populations are threatened by habitat destruction for coffee plantations. 1997 IUCN Red List of Threatened Plants Category R,II,V.
Etymology. The specific epithet was originally intended to refer to the very large leaflets, whereas amplifolia actually refers to the leaves. However, the epithet is not really a misnomer.
Specimens examined: COLOMBIA. Valle: Buenaventura, G Wallis 83 (LE); Rio Calima, R. Bernal 1460 (COL); San Isidro; D. Daly et al. 5971 (HUA, NY).
3. ZAMIA CHIGUA Seemann, Seem. Bot. Voy. Herald 6: 201, tab. 43. 1854.
LECTOTYPE: Tab. 43 in Seem. Bot. Voy. Herald 6: 1854. (fide Stevenson & Sabato, 1986).
Aulacophyllum ortgiesii Regel, Gartenflora 25:141-143.1876. TYPE: COLOMBIA. G. Wallis 76 (HOLOTYPE: LE).
Stem arborescent, to 2 m tall and 15 cm diam., wrinkled in appearance. Cataphylls triangular basally, lanceolate apically, 3-6 cm long, 2-3 cm wide. Leaves 3-15, 0.5-3 m long; petiole to 1 m long, very densely prickled; rachis with 30-80 (less in juvenile plants) pairs of imbricate leaflets, densely prickled in lower half. Leaflets imbricate, long-lanceolate, and subfalcate, chartaceous to membranous, margins entire, the larger median ones 10-30 cm long, 1-1.5 cm wide. Pollen strobili cream to light yellow, cylindrical, 10-20 cm long, 2-3 cm diam. Ovulate strobili tan to light brown, narrowly ovoid to cylindrical, 20-30 cm long, 8-12 cm diam. Seeds ovoid, red. 2n = 16 (Norstog, 1981).
Distinguishing features." Zamia chigua is the most fernlike of the Central American species of Zamia because of its long graceful leaves with numerous imbricate slender leaflets. It is also the species with the most numerous prickles, which are quite stout and often branched. The trunk is quite heavy because of its large amount of water-retentive parenchyma and often has a wrinkled appearance, particularly in large plants.
Distribution: Zamia chigua is found in the Chiriqui region of Panama and is disjunct in the Choco of Colombia (Fig. 2). In Colombia, Z. chigua is found in lowland rain forest, whereas known localities from Panama are 600-1200 m. This species is probably present on the slopes of Cerro Pirre and the western slopes of Cordillera de Jurado in Darien, Panama, and adjacent Colombia but has yet to be collected there.
Conservation status: Zamia chigua is quite common locally in both Panama and the Choco of Colombia. Its only threat seems to be from habitat destruction. It sets seed locally, but nothing is yet known about its reproductive biology. 1997 IUCN Red List of Threatened Plants Category R, II,V.
Etymology: The specific epithet is derived from the name used for cycads by indigenous people in the Choco, Colombia.
Notes: In the past there has been some confusion concerning the identity of Zamia chigua (Norstog, 1986; Sabato, 1990). The reason for this was the lack of typification of various Zamia species and the use of the common name of "chigua" by indigenous people in the Choco of Colombia. The common name "chigua" is apparently applied to several species of Zamia. As a result of this confusion, Z. roezlii Linden was thought to be Z. chigua, and the latter was referred to as Z. "helecho" in horticulture. Thus, the chromosome numbers attributed to Z. chigua by Norstog (1980, 1981) were in fact from plants of Z. roezlii (Norstog, 1986).
Specimens examined: COLOMBIA. Choco: Quibdo, R. Bernal et al. 1082 (COL. FTG, NY): J. Cuatrecasas & M. del Llano 24114 (US), E. Forero & R. Jaramillo 2514 (COL, MO), E. Forero et al. 5399, 9530 (COL, MO), A. Juncosa 1509 (MO, NY), E. P. Killip 35260 (US), Santa et al. 1148, 1151 (HUA, NY), Wilder et al. s.n. (F); Corcovado, J. W. Kress & B. Echeverry 89-2570 (SEL, US), T. Plowman 12027 (F, NY). Valle: Bajo Calima, M. Balick et al. 1633 (COL, JAIAM, NY), R. Bernal 1461 (COL, MO, NY), L. Bussel s.n. (FTG), T. Croat 61328 (MO, NY), D. Daly et al. 5974 (HUA, NY), G Galeano 457 (COL, MO, NY), A. Gentry 35573 (COL, MO, NY); Buenaventura, P. Maas 2013 (U), R. Sanders 1780 (CUVC, FTG, INCIVA), J. Santa & D. Sanchez 1043 (HUA, NY).
4. ZAMIA DISODON D. W. Stevenson & S. Sabato, Flora de Colombia 21: 38-39 & Fig. 4. 2001. (Fig. 4).
[FIGURE 4 OMITTED]
TYPE: COLOMBIA. Antioquia: D. Restrepo et al. s.n. (HOLOTYPE: COL; ISOTYPE: NY).
Stem to 50 cm, 5-8 cm diam. Cataphylls triangular basally, linear-lanceolate apically, 3-6 cm long, 1-2 cm wide. Leaves 2-4, erect or slightly recurved, oblong, 50 cm long; petiole terete, to 25 cm long, sparsely armed with small prickles; rachis terete, usually unarmed, to 25 cm long, 3-5 pairs of leaflets. Leaflets membranaceous, elliptic, subfalcate, acute at apex, margins serrate and always with some doubly serrate teeth near the apex, the median ones 12-20 cm long, 6-10 cm wide. Strobili unknown.
Distinguishing features: Zamia disodon is the only cycad with doubly toothed leaflet margins. In addition, it is the only Zamia beside Z. hymenophyllidia with transparent leaflets. However, Z. hymenophyllidia has entire to minutely toothed margins. In many respects, Z. disodon looks like an acaulescent to short-trunked Z. obliqua with transparent biserrate leaflets.
Distribution: Known only from the type locality and one other nearby population in Antioquia (Fig. 2) and disjunct in a single locality in Huanuco, Peru. To be expected in the southern Darien of Panama.
Conservation status: Because Zamia disodon has been so rarely collected it is assumed that the species is very rare; however, it is apparently available in local markets (Ian Turner, pers. com.). Because cones have not been seen, reproduction is assumed to be minimal. According to Rodrigo Bernal, the habitat is severely threatened. More fieldwork is needed to assess the situation. Not yet listed in the IUCN Red List of Threatened Plants, but the status throughout its range would be I,II,I.
Etymology: The specific epithet is derived from the doubly serrate leaflets.
Specimen examined (PARATYPE): COLOMBIA. Antioquia: O. Haught 4782 (COL).
5. ZAMIA ENCEPHALARTOIDES D. W. Stevenson, Flora de Colombia 21:40 & Fig. 5. 2001. (Fig. 5).
[FIGURE 5 OMITTED]
TYPE: COLOMBIA. Santander: Rio Chicamocha, F. Gonzdlez 3581 (HOLOTYPE: COL; ISOTYPES: NY, U).
Stem arborescent, to 2 m tall and 25 cm diam. Cataphylls cuneate basally and acuminate apically, to 2 cm wide and 5 cm long. Leaves 10-15, 0.5-1 m long; petiole inermis, 15-25 cm long; rachis inermis, 20-40 pairs of leaflets. Leaflets imbricate, lanceolate, cuneate basally, acute apically, margins entire and strongly revolute, the median ones 20-30 cm long, 1-3 cm wide. Pollen strobili cream to tan, long cylindric, 20-30 cm long, 3-5 cm diam.; peduncle 5-8 cm long. Microsporophylls with sterile tip composed of six steeply inclined facets surrounding a centrally depressed terminal facet, sporangia present on both the adaxial and abaxial surfaces of the fertile region. Ovulate strobili dark green, cylindrical to ovoid-cylindrical, 25-40 cm long, 10-15 cm diam. Seeds white to cream, 3-4 cm long, 1.5-2 cm diam.
Distinguishing features: The very coriaecous pungent entire margined leaflets and the large dark green seed cones. This species appears as a massive version of Z. inermis Vovides, Rees & Vazquez-Torres from Mexico.
Distribution: Endemic to Santander, Colombia (Fig. 2).
Conservation status. Known from two distinct populations. Plants and seedlings are abundant in both populations. The main threat appears to be encroaching farming. Not yet listed in the IUCN Red List of Threatened Plants, but the status would be R,II,R.
Etymology: The specific epithet is derived from the great similarity of leaf and cone morphology with the African genus Encephalartos Lehmann.
Historical notes." Zamia encephalartoides was first collected and illustrated in color in 1783 as result of an expedition, Real Expedicion Botanica del Nuevo Reyno de Granada, led by Jose Celistino Mutis. Unfortunately, no specimens survive, but the color plates are extant. There is no doubt but that the seed cone illustrated there is that of Z. encephalartoides. The seeds and seed dissections with embryo and suspensor are also illustrated. This is first known illustration of the latter. The sarcotesta of the seeds was illustrated as white, in contrast to the reds for other Zamia spp. (except Z. pseudoparasitica, which has a yellow sarcotesta). This was thought to be in error until the recent recollections of mature seeds, which are indeed white. In fact, the sarcotesta never really becomes soft and does break down, as in other Zamiaceae.
Specimens examined: COLOMBIA. Santander: Rio Chicamocha, 10 Jul 1996, A. Cadena et al. 3000 (COL, NY), F. A. Barkley & J. A. Molina 185, 273 (COL, US), F. Gonzalez 3580 (COL, NY), A. Henderson & R. Bernal 170 (COL, FTG, NY), C. Saravia 864 (COL).
6. ZAMIA HYMENOPHYLUDIA D. W. Stevenson, Flora de Colombia 21:43-44 & Fig. 6. 2001. (Fig. 6).
[FIGURE 6 OMITTED]
TYPE: COLOMBIA. Amazonas: D. Cardenas et al. 10089 (HOLOTYPE: COAH; ISOTYPE: NY).
Stem subterranean and tuberous, 2-4 cm diam. Cataphylls triangular basally, linear-lanceolate apically, membranaceous, 2-3 cm long, 0.5-1 cm wide. Leaves 2-5, erect, oblong, 30-70 cm long; petiole terete, to 35 cm long, armed with very small prickles; rachis terete, usually unarmed, to 20-35 cm long, 4-10 pairs of leaflets. Leaflets membranaceous, elliptic to elliptic-lanceolate, long-acuminate apically, cuneate to oblique basally, margins entire or rarely with a few diminutive apical teeth, 12-15 cm long, 1-2 cm wide. Pollen strobili brown, ovoid, 1-3 cm long, 0.1-0.3 cm diam.; peduncle 10-15 cm long. Microsporophylls with both abaxial and a few (1-3) adaxial sporangia. Ovulate strobili dark red-brown, cylindrical to ovoid-cylindrical, to 5 cm long, 3-4 cm diam.; peduncle to 15 cm long, 0.5 cm diam. Seeds red orange-red, 1-1.2 cm long, 0.5-0.8 cm diam.
Distinguishing features: Zamia hymenophyllidia is most similar to Z. melanorrhachis. Both species are unique in the cycads, with the presence of extremely long, thin peduncles (to 30 cm long and 1-3 mm diam.) terminated by very small pollen cones (1-3 cm long and 1-3 mm diam.). Zamia hymenophyllidia has membranous, elliptic, long-acuminate leaflets, in contrast to the papyraceous, lanceolate, generally acute leaflets of Z. melanorrhachis. The leaflet margins of Z. hymenophyllidia are generally entire and, if toothed, the teeth are inconspicuous and apical. In contrast, Z. melanorrhachis has well-developed marginal teeth. Living plants of Z. melanorrhachis have a dark purple to black petiole and rachis, a feature not found in Z. hymenophyllidia.
Distribution: Only four small populations are known, three in southeastern Amazonian Colombia (Fig. 7) and one in adjacent northeastern Peru.
[FIGURE 7 OMITTED]
Conservation status: Zamia hymenophyllidia was discovered only in the past three years from four small populations. The plants are reproductive and produce seeds and seedlings. Little is known about its biology and distribution, but the paucity of collections indicates that it is rare. Not yet listed in the IUCN Red List of Threatened Plants, but the status throughout its range would be R,II,R.
Etymology: The specific epithet is derived from the extremely thin, almost transparent leaflets.
Specimens examined: COLOMBIA. Amazonas: D. Cardenas et al. 8473, 8477 (COAH), A. Gentry & J. Villa-Lopera 60827 (MO, NY), R. Lopez 5268, 5275 (COAH).
7. ZAMIA LECOINTEI Ducke, Arch. Jard. Bot. Rio de Janeiro 1: 9-10. Tab. 1. 1915. (Fig. 8).
[FIGURE 8 OMITTED]
TYPE: BRAZIL. Para: Rio Erepecuru, 2 Oct 1913, Ducke MG 15027 (HOLOTYPE: MG).
Zamia obidensis Ducke, Arch. Jard. Bot. Rio de Janeiro 3: 20. tab. 1. 1922. TYPE: BRAZIL. Para: Rio Branco de Obidos, Mar 1918, Ducke s.n. (Museu Goeldi 17015) (HOLOTYPE: MG; ISOTYPE F).
Zamia ulei subsp. lecointei (Ducke) Ducke, Arch. Inst. Biol. Veget. Rio de Janeiro 2: 27-28. 1935.
Zamia jirijirimensis R. E. Schultes, Mutisia 15: 2-5. Fig. p. 5. s.n., 1953. TYPE: COLOMBIA. Amazonas: Rio Apaporis, Raudal de Jirijirimo, Mar 1951, R. E. Schultes 12101 (HOLOTYPE: GH-2 sheets).
Stem subterranean and tuberous, 5-8 cm diam. Cataphylls triangular basally, linear-lanceolate apically, 3-6 cm long, 1-2 cm wide. Leaves 2-4, erect or slightly curved, oblong, 1-2 m long; petiole terete, to 75 cm long, sparsely armed, with stout prickles; rachis terete, usually unarmed, to 1 m long, 30-40 pairs of leaflets. Leaflets subcoriaceous to coriaceous, linear-lanceolate, subfalcate, long-acuminate at apex, margins entire or rarely with 2-3 indistinct teeth near the apex of lower margin, the median ones 30-37 cm long, 1-2 cm wide. Pollen strobili 2-6, cylindrical, cream to light brown, 6-10 cm long, 1-2 cm diam.; peduncle 10-20 cm long. Ovulate strobili usually solitary, brown, 10-15 cm long, 3-5 cm diam.; peduncle 5-8 cm long. Seeds with a red outer fleshy layer, ovoid, 3 cm long, 2 cm diam. 2n = 16 (Caputo et al., 1996).
Distinguishing features: Zamia lecointei is most similar to Z. muricata. The two taxa share a common distribution pattern but are not sympatric and prefer different habitats. Zamia lecointei grows in open dry areas of sandy to pure sand soils, whereas Z. muricata grows as an understory plant in mesic conditions in wet clay soils. Consequently, Z. lecointei has subcoriaceous to coriaceous, linear-lanceolate, subfalcate leaflets that are entire or with only 1-3 indistinct apical teeth. In contrast, Z. muricata has chartaceous to papyraceous, oblong-lanceolate to lanceolate, inequilateral leaflets that are clearly denticulate in the upper half of both margins. Often in the open in the direct sun or as an understory in secondary vegetation, the leaflets become more narrower and quite coriaceous with entire margins, as opposed to more shaded conditions, where the leaflets are wider, thinner, and with well-developed serrations in the upper third. Plants growing in extremely dry, sandy soil were described as Z. jirijirimensis.
Distribution: In Amazonas and Bolivar, Venezuela; Para, Brazil, north of the Amazon River to central Colombia (Fig. 7) and Brazil.
Conservation status: Zamia lecointei is most common in Bolivar, Venezuela, in both pristine and disturbed habitats. Seed set appears high, and the populations are not, at this time, threatened by development or destruction. Collections in Colombia indicate that it is locally common with good seed set. It does well in minor disturbed situations. Not listed in the IUCN Red List of Threatened Plants, but the status throughout its range would be R,II,R.
Eponymy: The specific epithet honors Paul LeCointe, who lived in Obidos, Brazil, and accompanied Adolf Ducke when the species was discovered.
Systematic and nomenclatural history: Ducke (1915) described Zamia lecointei and mentioned another probable new Zamia, which he described as Z. cupatiensis in 1922. The type, illustration (Ducke, 1915: tab. 1), and description of Z. lecointei all show linear-lanceolate leaflets. Ducke's (1915) concept of Z. ulei is presented in Table 2 of the same paper; this bears little resemblance to the type or description (Dammer, 1907) of Z. ulei, which has ovate-lanceolate to elliptic leaflets. As a result of his misconception, Ducke described Z. cupatiensis in 1922. The description and photograph of Z. cupatiensis (Ducke, 1922: tab. 2) match the photograph and isotypes of Z. ulei. In the same paper, Ducke (1922) also described Z. obidensis, which was intermediate between his Z. lecointei and his Z. cupatiensis. Because Ducke mistakenly thought that Z. ulei had linear-lanceolate leaflets, he (1935) considered Z. lecointei to be a subspecies, Z. ulei subsp, lecointei. This problem was compounded by Schuster (1932). As a result, Schultes (1953) redescribed Z. lecointei as Z. jirijirimensis. However, the type specimens for these two names are identical. Thus, Z. cupatiensis is a synonym of Z. ulei, and Z. jirijirimensis is a synonym of Z. lecointei. Moreover, Z. obidensis is a shade and/or juvenile form of Z. lecointei.
Specimens examined: COLOMBIA. Antioquia: Remedios, R. Callejas et al. 5250 (HUA, NY). Amazonas: Rio Apaporis, R. Bernal et al. 1237, 1239, 1240, 1241 (COL, NY); Rio Caqueta, G. Galeano et al. 1187, 1976 (COL, NY); R. E. Schultes & I. Cabrera 12465, 13511, 14640, 14956, 17660, 17663 (GH); L. Urrego G. et al. 623, 662 (NY).
8. ZAMIA MANICATA Linden ex Regel, Acta Horti Petrop. 4(4): 310. 1876. (Fig. 9).
[FIGURE 9 OMITTED]
NEOTYPE: Tafel 926, fig. e in Gartenflora 27: 1878. (fide Stevenson & Sabato, 1986).
Zamia madida R. E. Schultes, Bot. Mus. Leaf. Harv. Univ. 18(4): 114-115. Pl. 18. 1958. TYPE: COLOMBIA. R. E. Schultes & I. Cabrera 18694 (HOLOTYPE: GH-2 sheets!).
Stem subterranean, globose to subcylindric, 5-10 cm diam. Cataphylls triangular basally, long-acuminate apically, 3-8 cm long, 1-2 cm wide. Leaves 3-10, 0.5-2 m long; petiole 0.2-1 m long, slightly to densely prickled; rachis often with prickles in lower third, with 10-30 pairs of leaflets. Leaflets with distinct petiolule and abaxial gland-like collar at the juncture of the lamina, oblong to long-elliptic, margins serrate in upper third, cuneate basally, acute to acuminate apically, the larger median ones 15-35 cm long, 3-7 cm wide. Pollen strobili cream to tan, cylindrical, 4-6 cm long, 1-1.5 cm diam.; peduncle 15-30 cm long. Ovulate strobili wine-red to dark red-brown, cylindrical to ovoid-cylindrical, 10-15 cm long, 4-7 cm diam. Seeds red, 1-1.5 cm long, 0.5-0.8 cm diam. 2n = 18 (Caputo et al., 1996).
Distinguishing features: The petiolule and gland-like collar occur among cycads only in Zamia manicata (Stevenson, 1990a). However, they are not present in seedling leaves, only diminutively present in juvenile leaves, and become distinct only in adult leaves. Also, in transplanted adult plants these structures may not be produced in the first set of leaves after transplanting.
Distribution: Zamia manicata occurs in rain forest and secondary forest from 100 m to 1000 m in the Darien of Panama and contiguous Colombia (Fig. 10).
[FIGURE 10 OMITTED]
Conservation: Zamia manicata is locally abundant and often found in coffee plantations, at the margins of pastures, and in secondary vegetation. It sets seed in all of these habitats. However, it is threatened by continual disturbance. 1997 IUCN Red List of Threatened Plants Category R,II,V for Colombia and R,II,R for Panama.
Etymology: The specific epithet refers to the gland-like collar at the leaflet base.
Systematic and nomenclatural history: Somehow Schuster (1932) confused Zamia manicata with Z. obliqua and placed the former in synonymy with the latter. Schuster's description is a mixture of the two species. However, Braun (1875) described Z. obliqua with sessile elliptic to ovate-elliptic ("obelliptic") leaflets and trunks to 2.5 m and never mentioned petiolules or gland-like collars because these characters do not occur in Z. obliqua. In fact Schuster's concept of Z. obliqua was a plant with the trunks and strobili of Z. obliqua and the leaves of Z. manicata. Moreover, he described the petioles as unarmed, when, in fact, anyone who has collected either of these species can attest to the numerous prickles. In contrast, Gomez's (1982) concept of Z. obliqua is, in fact, that of Z. manicata. Because of the confusion instigated by Schuster (1932), Schultes (1958) redescribed Z. manicata as Z. madida, and the description of Z. obliqua by Gomez (1982) is that of Z. manicata, with both Z. manicata and Z. madida listed in synonymy. Beside the presence of petiolules and gland-like collars in Z. manicata and their absence in Z. obliqua, salient differences between these two species are subterranean stem, oblong to long elliptic (to 35 cm) leaflets, long pedunculate (15-30 cm), polleniferous strobili, microsporophylls with microsporangia only on the abaxial surface, and wine-red to dark red-brown ovulate strobili in Z. manicata. In contrast, Z. obliqua has aerial trunks to 5 m, elliptic to obovate leaflets to 10 cm long, short pedunculate (2-5 cm), polleniferous strobili, microsporophylls with microsporangia on both the adaxial and abaxial surfaces, and tan to light brown ovulate strobili.
Specimens examined: COLOMBIA. Antioquia: Acandi, L. E. Forero 614 (COL); Mutata, Bernal et al. 601 (COL), R. Callejas et al. 5665, 5772 (HUA, MO, NY), Betancur et al. 5999 (COL, NY), R. E. Schultes & I. Cabrera 18640, 18679 (GH), Turbo, Bernal et al. 447 (COL), O. Haught 4820 (COL, US), J. Santa & J. Brand 835 (COL, HUA); Villa Arteaga: W. H. Hodge 7041 (US). Choco: Rio Tigre, A. Gentry & L. E. Aguirre 15190 (COL, MO); Rio Sucio, E. Forero & R. Jaramillo 1577 (COL, MO), H. Leon 572 (MO, COL); Rio Tendal, S. Zuluaga 1033 (COL).
9. ZAMIA MELANORRHACHIS D. Stevenson, Flora de Colombia 21: 55 & Fig. 9. 2001. (Fig. 11).
[FIGURE 11 OMITTED]
TYPE: COLOMBIA. Cordoba: D. Stevenson et al. 695 (HOLOTYPE: COL; ISOTYPES: HUA, NY, U).
Stem subterranean and tuberous, 5-8 cm diam. Cataphylls triangular basally, linear-lanceolate apically, 2-5 cm long, 1-2 cm wide. Leaves 2-5, erect, oblong, 50 cm long; petiole terete, to 25 cm long, dark purple to black when fresh, armed with very small prickles; rachis terete, usually armed with very small prickles in lower half, to 20-30 cm long, 4-10 pairs of leaflets. Leaflets papyraceous, lanceolate, acute at apex, cuneate at base, margins serrate in upper two-thirds, 12-15 cm long, 1-2 cm wide. Pollen strobili cream to tan, ovoid, 1-3 cm long, 0.5-1 cm diam.; peduncle 30-50 cm long, 0.2-0.4 diam. Microsporophylls with both abaxial and a few (1-3) adaxial sporangia. Ovulate strobili wine-red to dark red-brown, cylindrical to ovoid-cylindrical, 5-8 cm long, 3-4 cm diam. Seeds red, 1-1.5 cm long, 0.5-0.8 cm diam.
Distinguishing features: As discussed above, Zamia melanorrhachis is most similar to Z. hymenophyllidia, from which it differs in having papyraceous, lanceolate, generally acute leaflets with well-developed marginal teeth. In contrast, Z. hymenophyllidia has membranous, elliptic, long-acuminate leaflets with generally entire or inconspicuous apical teeth. Additionally, living plants of Z. melanorrhachis have a dark purple to black petiole and rachis, a feature not found in Z. hymenophyllidia.
Distribution: Endemic. Ranging from north central Colombia to Amazonian Colombia (Fig. 7).
Conservation status: Zamia melanorrhachis is known from only three widely spaced localities. Its paucity in collections may well represent the fact that it is found in poorly explored areas. In fact, more recent collections indicate that it is more widely distributed than previously thought. This is supported somewhat by the fact that it grows well and regenerates in and near native gardens. Not yet listed in the IUCN Red List of Threatened Plants, but the status throughout its range would be R,II,R.
Etymology: The specific epithet is derived from the dark brown to dark purple rachis of the leaves of living plants.
Specimens examined: COLOMBIA. Amazonas: Rio Loretoyacu, I. Cabrera 3351 (COL). Cordoba: Montelibano, F. J. Roldan et al. 1491, 1523 (COL, HUA, IVY). Meta: R. Callejas & O. Marulanda 5911 (HUA, MO). Santander: Barrancabermeja, O. Haught 1447, 1578, 2101 (BM, COL, F, GH, P, US).
10. ZAMIA MONTANA A. Braun, Monatsber. k. Akad. Wiss. Berlin, Apr 1875: 376-377. 1875. (Fig. 12).
[FIGURE 12 OMITTED]
NEOTYPE: COLOMBIA. Antioquia: 1750 m, Zarucchi et al. 5724 (NEOTYPE: NY; ISONEOTYPES: COL, MO, fide Stevenson, 2001).
Aulacophyllum montanum (A. Braun) Regel, Gartenflora 25: 141. 1876.
Stem arborescent, 0.5-1.5 m tall, 10-20 cm diam. Cataphylls triangular basally, long-acuminate apically, 3-5 cm long, 2-3 cm wide. Leaves 2-5, 1-2 m long; petiole with only a few prickles, 30-70 cm long; rachis with 8-12 pairs of leaflets. Leaflets oblong-lanceolate, cuneate basally, acuminate apically, margins sparsely serrulate in upper third, the median ones 18-30 cm long, 3-7 cm wide. Pollen strobili tan, cylindrical to ovoid-cylindrical, 6-8 cm long, 1.5-2 cm diam.; peduncle 2-4 cm long. Ovulate strobili brown, cylindrical to ovoid-cylindrical, 20-30 cm long, 8-10 cm diam. Seeds red, 1-1.5 cm long, 0.5-0.8 cm diam.
Distinguishing features: Zamia montana was described in 1875 by Alexander Braun (one of the most famous eclectic German botanists of the nineteenth century) from material collected by Gustav Wallis in Colombia. The species was collected once again in 1888 by Kalbreyer and then not seen again for 100 years. The Wallis and Kalbreyer collections were lost, and no type specimen was extant, resulting in some doubt about the existence of the species until its recent rediscovery in the field in the 1980s and with Kalbreyer's specimens just recently rediscovered at Kew. Zamia montana is readily identified by its obviously long, obovate leaflets with shallow grooves between the veins of the upper surface. Zamia montana grows in wet montane forest at 1800-2000 m, the highest elevation known for any neotropical cycad.
Distribution: Endemic. Known only from collections at and near the neotype locality (Fig. 7).
Conservation status: Zamia montana is extremely rare and is unknown in cultivation. Its habitat is also extremely threatened by logging activities. In fact, it may well be extinct in the wild, because the only known population occurs in an area that was recently logged. 1997 1UCN Red List of Threatened Plants Category V,II,V.
Etymology: The specific epithet refers to the submontane to montane habitat of the species.
Specimens examined: COLOMBIA. Antioquia: Kalbreyer 1928 (K-3 sheets), Sanchez et al. 700, 1185 (COL, HUA), Sanchez et al. 597, 816, 1185 (HUA).
11. ZAMIA MURICATA Willdenow, Sp. PI., ed. 4, 4: 847-848. 1806.
TYPE: VENEZUELA. Guarico: prope Porto Cabello, Humboldt & Bonpland s.n. in Willd. Herb. n. 18536 (HOLOTYPE: B-W; ISOTYPE: U).
Zamia gutierrezi Sauv., Anal. Acad. Cienc. Med., Fisc., & Nat. Haban. 5: 54. 1868. TYPE: CUBA. Pinar del Rio: cult. Hort. Blain, Rangel (HOLOTYPE: HAC; ISOTYPES: F, NY).
Zamia latifolia Lodd. ex Miquel, Tijdschr wis-en Natuurk. Wet. 2(4): 298. 1849. Basionym: Z. muricata var. obtusifolia Miquel, Tijdschr. nat. Gesch. Physiol. 10(1): 71-72. 1843.
Zamia media Jacq. var. gutierrezi (Sauv.) J. Schust., in Engl., Pflanzenr. 4(1): 154. 1932.
Zamia muricata var. angustifolia Miquel, Monogr. Cycad. p. 66. 1842. TYPE: ex Horto Spaarberg. Miquel s.n. (HOLOTYPE: U).
Zamia muricata var. obtusifolia Miquel, Tijdschr. nat. Gesch. Physiol. 10(1): 71-72. 1843. NEOTYPE: Tab. VII, fig. a, in Linnaea 19(4): 1847. (fide Stevenson & Sabato, 1986).
Stem semihypogeous to slightly epigeous, to 15 cm tall, 3-8 cm diam. Cataphylls triangular basally, linear-lanceolate apically, 3-8 cm long, 1-2 cm wide. Leaves 2-6, 1-2 m long, oval to elliptic; petiole 0.5-1 m long, often with a shallow groove on the upper side, armed with small, 1-2 mm-long prickles on the lower side; rachis 0.5-1 m long, with 6-12 subopposite pairs of leaflets, rarely armed with prickles in the lower third. Leaflets chartaceous to papyraceous, inequilateral, oblong-lanceolate to lanceolate, long-acuminate at apex, constricted at base and articulated with rachis by means of a callous ring of tissue, denticulate in upper half, 15-20 cm long, 2-4 cm wide. Pollen strobili 2-6, cylindrical, cream to light brown, 6-10 cm long, 1-2 cm diam.; peduncle 10-20 cm long. Ovulate strobili usually solitary, brown, 10-15 cm long, 3-5 cm diam.; peduncle 5-8 cm long. Seeds with a red outer fleshy layer, ovoid, 3 cm long, 2 cm diam. 2n = 24 (Norstog, 1980).
Distinguishing features: Zamia muricata is most similar to Z. lecointei. The two taxa share a common distribution pattern but are not sympatric and prefer different habitats. Zamia muricata grows as an understory plant in mesic conditions in wet clay soils, whereas Z. lecointei grows in open dry areas of sandy to pure sand soils. Zamia muricata has chartaceous to papyraceous, oblong-lanceolate to lanceolate, inequilateral leaflets that are clearly denticulate in the upper half of both margins. In contrast, Z. lecointei has subcoriaceous to coriaceous, linear-lanceolate, subfalcate leaflets that are entire or with only 1-3 indistinct apical teeth.
Distribution: Northeastern and coastal Colombia (Fig. 7) to the central coastal area of Venezuela.
Conservation status. In coastal Venezuela the species does well in both undisturbed habitats and at the margins of local gardens. Its status in Colombia is more enigmatic because very few localities are known, and these are in quite remote areas, so there is insufficient data. 1997 IUCN Red List of Threatened Plants Category R,II,I for Colombia and R,II,R for Venezuela.
Etymology: The specific epithet refers to the sharp marginal teeth of the leaflets. At the time this species was described, the only other known species of Zamia were from the West Indies, and all of them had inconspicuous dull marginal teeth.
Specimens examined: COLOMBIA. Boyaca: O. Haught 2601 (COL, US). La Guajira: R H. Allen 3355 (MO, US), C. Saravia & M. E. de Saravia 3584 (COL, US), A. Sugden 62, 21l, 238 (COL). Meta: San Martin, O. Marulanda 769 (HUA, MO). Santander: Puerto Berrio, O. Haught 1622, 1682, 1717 (F, US).
12. ZAMIA OBLIQUA A. Braun, Monatsber. k. Akad. Wiss. Berlin, Apr 1875: 376. 1875. (Fig. 13).
[FIGURE 13 OMITTED]
TYPE: COLOMBIA, Seemann 1569 (NEOTYPE: BM-2 sheets!; ISONEOTYPE: K; fide Stevenson & Sabato, 1986).
Zamia obliqua Regel ex Ducos, Ill. hortic. 24: 140. Planche 289.1877. LECTOTYPE: Planche 289 (fide Stevenson & Sabato, 1986) nomen illegit. Later homonym for Z. obliqua A. Braun.
Stem arborescent, 0.5-5 m tall, 5-12 cm diam. Cataphylls triangular basally, long-acuminate apically, 3-5 cm long, 2-3 cm wide. Leaves 5-20, 1-2.5 m long; petiole with numerous small prickles, 30-70 cm long; rachis with prickles in lower third, 10-20 pairs of leaflets. Leaflets elliptic to obovate, obliquely cuneate basally, acuminate apically, margins serrulate in upper third, the median ones 5-10 cm long, 3-6 cm wide. Pollen strobili cream to tan, cylindrical to ovoid-cylindrical, 4-6 cm long, 1-1.5 cm diam.; peduncle 2-4 cm long. Microsporophylls with sterile tip composed of six steeply inclined facets surrounding a centrally depressed terminal facet, sporangia present on both the adaxial and abaxial surfaces of the fertile region. Ovulate strobili cream to tan, cylindrical to ovoid-cylindrical, 15-25 cm long, 5-8 cm diam. Seeds red, 1-1.5 cm long, 0.5-0.8 cm diam. 2n = 18 (Norstog, 1980).
Distinguishing features: Zamia obliqua is one of the most beautiful of the New World cycads, with its straight, slender, smooth, gray trunks of 5 m bearing some 20 leaves. As discussed above under Z. manicata, Z. obliqua has been confused with that species, but there is no close resemblance between them other than the fact that they belong to the same genus. Acaulescent juvenile plants of Z. obliqua are most similar to Z. ulei. However, the leaflets of Z. obliqua are always oblique basally, whereas the leaflets of Z. ulei are symmetrical.
Distribution: Zamia obliqua occurs in primary and secondary rain forest from near sea level to 500 m in southern Panama to the southern Choco of Colombia (Fig. 7).
Conservation status: Little was known about threats to populations of Zamia obliqua when the 1997 IUCN Red List was being compiled, but recent surveys indicate that the species is highly endangered in Panama as a result of habitat destruction. Little is known about population size and reproduction in Colombia, but seed cones do occur in larger individuals. Zamia obliqua produces copious seed but is vulnerable because the plants have to reach a stature of over a meter-tall trunk before producing cones. Thus, habitat disturbance makes this species particularly vulnerable. 1997 IUCN Red List of Threatened Plants Category I,II,R in Colombia and I,II,V in Panama.
Etymology: The specific epithet refers to the oblique insertion and shape of the leaflet bases.
Specimens examined: COLOMBIA. Antioquia: Nuqui, Bernal et al. 744 (COL). Choco: Acandi, Fonnegra et al. 2790, 2905 (COL, HUA, NY); Cabo Corrientes, S. Kiem & K. Norstog 36 (FTG), R. Bernal et al. 744, 749, 757 (COL, MO), Betancur et al. 6048 (COL, NY); C. La Rotta 699 (COL); Jequedo, A. Gentry & E. Renteria 24097 (COL, MO, NY); Rio Condoto, E. P. Killip 35162 (US); Rio San Juan, E. Forero et al. 4510, 9530 (COL, MO). Valle: Rio Calima, J. Cuatrecasas & V. Patino 27459 (COL, US).
13. ZAMIA POEPPIGIANA Martius & Eichler, Fl. Bras. 4(1): 414-416: tab. 109. 1863.
TYPE: PERU. Maynas Alto: Toache River, 1830, Poeppig s.n. (LECTOTYPE: F ex Herb. Musei Palat. Vindob.; ISOLECTOTYPE: GH ex Herb. Musei Palat. Vindob.; fide Stevenson & Sabato, 1986).
Zamia lindenii Regel ex Andre, Ill. hortic. 22: 23. Planche 195. 1875. LECTOTYPE: Planche 195 in Ill. hortic. 23: 1875. (fide Stevenson & Sabato, 1986).
Aulacophyllum lindenii (Regel ex Andre) Regel, Gartenflora 25: 141. 1876.
Zamia baraquiniana Regel, Acta Horti petrop. 4(4): 308-309. 1876. TYPE: ex Horto Petropolitano, Regel s.n. (HOLOTYPE: LE; ISOTYPE: K).
Zamia wielandii Schuster, Pflanzenr. 99: 149. 1932. nomen illegit. Superfluous name for Z. baraquiniana Regel.
Stem arborescent, to 3 m tall and 25 cm diam. Cataphylls cuneate basally and acuminate apically, to 2 cm wide and 4 cm long. Leaves 10-15, 1-3 m long; petiole with numerous small prickles, 30-70 cm long; rachis with prickles in lower third, 20-40 pairs of leaflets. Leaflets long-lanceolate, falcate basally, acuminate to acute apically, margins strongly spinulose in upper third with serrations at nearly 90[degrees] and 0.5-1 cm apart, the median ones 15-40 cm long, 2-4 cm wide. Pollen strobili cream to tan, long cylindric, 20-30 cm long, 3-5 cm diam.; peduncle 5-8 cm long. Microsporophylls with sterile tip composed of six steeply inclined facets surrounding a centrally depressed terminal facet. Ovulate strobili tan to brown, cylindrical to ovoid-cylindrical, 25-40 cm long, 10-15 cm diam. Seeds red, oblong, distinctly flattened, 1-1.5 cm long, 0.5-0.8 cm diam. 2n = 18 (Norstog, 1980).
Distinguishing features: Zamia poeppigiana is readily identified by its falcate linear leaflets with evenly spaced teeth at nearly right angles to the margin. Zamia poeppigiana and Z. lindenii are here considered conspecific. The types of both are identical, but the former is from the lower Pacific Andean slopes of Ecuador, whereas the latter is from the lower Amazonian slopes of Peru and Colombia. The seeds of Z. poepppigiana are unique within Zamia because of their somewhat flattened, oblong shape. In contrast, the seeds of Z. lindenii are reported to be unflattened and oval in shape, as in all other known species of Zamia, but this needs to be confirmed with herbarium material.
Distribution: Known from the coastal plains and foothills of the Cordillera Occidental in Ecuador and the rich humus soils of Acre, Brazil, and southwestern Colombia (Fig. 10).
Conservation Status: Zamiapoeppigiana is widely but sporadically distributed. Local populations exhibit good seed set and seedling establishment. Unlike Z. obliqua, Z. poeppigiana appears to produce seed cones when the stems are not yet arborescent, thus reducing the threat from habitat destruction. Not yet listed in the IUCN Red List of Threatened Plants.
Eponymy: The specific epithet honors Eduard Poeppig, who first collected the species in Peru.
Specimens examined: COLOMBIA. Huila: La Puenta, F. R. Fosberg 19304 (P, US); Algeciras, E. L. Little 9273 (COL, P, US). Meta: Rio Guejara, W. Philipson 2368 (BM). Tolima: Alto del Oso, G. Woronow 6992 (LE); La Colona, E. L. Little 8758 (COL, US); Upper Magdalena Valley, H. von Eggers 14034 (K).
14. ZAMIA ROEZLII Linden, Linden Catalogue des plantes nouvelles no. 90, p. 10. 1873.
NEOTYPE: Planches 133-134 in Ill. hortic. 20: 1873. (fide Stevenson & Sabato, 1986).
Aulacophyllum roezlii (Linden) Regel, Gartenflora 25: 141. 1876.
Stem arborescent, to 7 m tall. Leaves 5-10, 1-3 m long; petiole 0.5-1 m long, sparsely to densley prickled; rachis with 10-20 pairs of leaflets, occasionally with a few prickles in the lower third. Leaflets linear-lanceolate, grooved between the veins on the adaxial surface, cuneate basally, acute apically, margins entire, 30-50 cm long, 12-15 cm wide. Pollen strobili cream to tan, cylindrical to elongate-cylindrical, 20-30 cm long, 4-6 cm diam. Ovulate strobili brown, short pedunculate, cylindrical to ovoid cylindrical, 30-60 cm long, 10-20 cm diam. Seeds red, ovoid, 1.5-2.5 cm diam. 2n = 22, 24, 25, 26 (Norstog, 1981).
Distinguishing features: Zamia roezlii is the largest South American Zamia and is unmistakable, with its massive trunk, leaves, and strobili. This species would appear to part of a complex composed of Z. dressleri, Z. neurophyllidia, and Z. skinneri in Panama, Z. amplifolia and Z. roezlii in the Choco of Colombia and adjacent Ecuador, and Z. wallisii in northern Antioquia, Colombia. This grouping is based upon the common occurrence of the plicate appearance of the leaflets of these species. This character, along with simultaneous rather than sequential leaf production, prompted Regel (1876) to erect the segregate genus Aulacophyllum. However, no other synapomorphies have been found to support Aulacophyllum as a genus (Sabato, 1990). Moreover, the distinction between simultaneous and sequential leaf production in Zamia seems problematic at best. However, Zamia roezlii is readily distinguishable from other species with deeply grooved leaflets by its falcate, linear, entire leaflets.
Distribution: Along coastal Choco, Colombia (Fig. 10) and contiguous coastal Ecuador.
Conservation status: Zamia roezlii is locally abundant and produces very large seed cones and thus numerous seeds and seedlings. However, seed cones are produced by arborescent plants and under continual disturbance seed production will be severely diminished, resulting in high vulnerability. 1997 IUCN Red List of Threatened Plants Category R,II,V.
Eponymy: The specific epithet honors Benedict Roezl, a prodigious plant collector who traveled throughout Mexico, Central America, and South America in the latter half of the nineteenth century and who first collected the species.
Specimens examined: COLOMBIA. Amazonas: Rio Cahuinari, C Penuela et al. 983 (COL). Choco: Baudo, H. P. Fuchs et al. 21902, 22107 (COL); Quebrada Togoroma, Killip & Cuatrecasas 39129 (COL, F). Narino: Barbacoas, A. Alston 8485 (BM); Tangaria, R. Bernal & G Galeano 892 (COL, NY), R. Bernal & B. Corredor 1457. 1459 (COL, NY); Puerto Merizalde, P. Fr. Gaspar Soret L. s.n. (COL). Valle: Buenventura Bay: L. Bussel s.n. (FTG); Charimal, P. Fr. Gaspar Soret L. s.n. (COL); Bahia Malaga, A. Gentry et al. 53395, 53397 (COL, MO, US); Rio Calima, S. Kiem & K. Norstog 31 (FTG), S. Kiem & K. Norstog 38 (FTG), S. Kiem s.n. (FTG), E. P. Killip & J. Cuatrecasas 38967 (COL, US, F); Cordoba, E.P. Killip & H. Garcia 33337, 33410 (BM, COL, F, P, US); Rio Naya, A. Gentry & A. Juneosa 40710 (MO, NY, US); Sabaletas, G. Zammas 95-1 (FTG).
15. ZAMIA ULEI U. Dammer, Verh. Bot. Vereins Prov. Brandenburg 47: 117-118. 1907.
TYPE: BRAZIL. Cachoeira oberer Rio Jura, May 1901, E. Ule 5523 (LECTOTYPE: HBG; ISOLECTOTYPES: L, G, MG, K, F--Fragment; fide Stevenson & Sabato, 1986).
Zamia cupatiensis Ducke, Arch. Jardim Bot. Rio de Janeiro 3: 20. Planche 1. 1922. LECTOTYPE: Planche 1. (fide Stevenson & Sabato, 1986).
Stem subterranean and tuberous, tapering distally, 4-6 cm in diam. Leaves 2-4, 1-1.5 m long, broadly ovate; petiole to 1 m long, terete, generally armed with numerous prickles; rachis to 50 cm long, with 3-6 pairs of subopposite leaflets, often armed with prickles in the lower third. Leaflets sessile, papyraceous to subcoriaceous, oblong-elliptic to elliptic-ovate, sometimes slightly falcate, obtuse, and constricted at base, acute to short-acuminate at apex, 12-15 teeth on each margin in the upper half, the median ones 12-20 cm long, 6-10 cm wide. Pollen strobili usually 2-5, tan, cylindrical, 6-10 cm long, 1-2 cm diam.; peduncle 6-8 cm long. Ovulate strobili usually solitary, brown, cylindrical, 18-20 cm long, 4-6 cm diam.; peduncle 8-10 cm long. Seeds red, ovoid to oblong, 15 mm long, 8 mm diam. 2n = 26 (Caputo et al., 1996).
Distinguishing features: Zamia ulei is similar to Z. obliqua, but the latter always has obliquely inserted and basally falcate leaflets, and Z. ulei always has symmetrical leaflets. Moreover, adult plants of Z. obliqua are arborescent, in contrast to the acaulescent stems of Z. ulei.
Distribution: North of the Amazon River in Parfi and Rio Branco, Brazil, and disjunct to the bordering regions of western Brazil and eastern Peru and Colombia (Fig. 10).
Conservation status: Zamia ulei is fairly common in sporadic populations throughout its range. Seed set and seedling establishment appear to be high. Not yet listed in the IUCN Red List of Threatened Plants, but the status throughout its range would be R,II,R.
Etymology: The specific epithet honors Eduard Ule, an Amazonian plant collector of the latter half of the nineteenth century who first collected the species in Brazil.
Specimens examined: COLOMBIA. Amazonas: Leticia, Z. Plowman 11799, 11800 (F, NY); Loretoyacu River, R. E. Schultes & G. A. Black 8366 (F).
16. ZAMIA WALUSII A. Braun, Monatsber. k. Akad. Wiss. Berlin, Apr 1875: 376. 1875.
TYPE: COLOMBIA. Stevenson et aL 582 (NEOTYPE: NY; ISONEOTYPES: FTG, HUA, JAUM, NAP, NY; fide Stevenson & Sabato, 1986).
Aulacophyllum wallisii (A. Braun) Regel, Gartenflora 25: 143-144. 1876.
Stem subterranean, 3-5 cm diam. Cataphylls ovate, 1-2 cm long, 2-3 cm wide. Leaves usually solitary (2-3), 0.5-1.5 m long; petiole 0.3-1 m long, sparsely to densely prickled; rachis with 2-5 pairs of leaflets, occasionally with a few prickles in the lower third. Leaflets with distinct petiolule, elliptic, grooved between the veins on the adaxial surface, cuneate basally, acuminate apically, margins serrate in upper third, the larger median ones 30-50 cm long, 12-15 cm wide. Pollen strobili cream to light tan, cylindrical to elongate-cylindrical, 5-8 cm long, 1-2 cm diam. Ovulate strobili unknown. 2n = 16 (Caputo et al., 1996).
Distinguishing features: Zamia wallisii is readily identified by its huge, elliptic leaflets, up to 30 cm wide, with deep grooves between the veins of the upper surface and the obvious petiolules. As Norstog and Nicholls (1997) have pointed out, Z. wallisii is similar to Z. dressleri, a species described from central Panama (Stevenson, 1993). Both species have subterranean stems and large leaves, with only 2-5 pairs of huge, deeply grooved leaflets with toothed margins. However, Z. dressleri lacks the distinctive petiolules found in Z. wallisii.
Distribution: Endemic. Known only from the neotype locality (Fig. 10).
Conservation: Zamia wallisii should be considered, along with Z. montana, as the most endangered species of Zamia in Colombia. Both are known only from single populations, and the seed cones of Z. wallisii are unknown. The presence of seedlings in the population indicate that reproduction does occur, but apparently rarely. According to Rodrigo Bernal, habitat destruction has become acute. 1997 IUCN Red List of Threatened Plants Category R,II,V.
Etymology: The specific epithet honors Gustav Wallis, a plant collector of the latter half of the nineteenth century who first collected the species.
Historical notes: Zamia wallisii was described in 1875 by Alexander Braun (one of the most famous eclectic German botanists of the nineteenth century) from material collected by Gustav Wallis in Colombia. The species was collected once again in 1888 by Kalbreyer and then not seen again for 100 years. Both the Wallis and Kalbreyer collections were lost, and no type specimen was extant, resulting in some doubt about the existence of the species until its recent rediscovery in 1980s and with Kalbreyer's specimens just recently rediscovered at Kew.
Specimens examined: COLOMBIA. Antioquia: Cinegetas, Kalbreyer 1927 (K-3 sheets); Frontino, R. Bernal et al. 735, 1255 (COL), Sanchez et al. 1728 (HUA).
Sabato (1990) provided a brief review of the distribution of Zamia in the West Indies and South American. The present study, with its delimitation of the species and their distribution patterns in Central and South America, makes possible some testable hypotheses on the phytogeography of Zamiaceae in this region and on species relationships for the taxa included in this treatment.
The present treatment recognizes two genera of the Zamiaceae as native in Colombia: Chigua, an endemic genus with two species, and Zamia, with 16 species. Of the 16 species of Zamia, five (Z. amplifolia, Z. encephalartoides, Z. melanorrhachis, Z. montana, and Z. wallisii) are endemic to Colombia, three (Z. chigua, Z. manicata, and Z. obliqua) extend into Panama to the north, another two (Z. roezlii and Z. poeppigiana) extend southward into Ecuador and Peru, one (Z. muricata) extends northward to coastal Venezuela, and another four (Z. amazonum, Z. hymenophyllidia, Z. lecointei, and Z. ulei) are found principally in the Amazon Basin. Based upon the limited available collections of the Zamiaceae in Central and South America, there appear to be four floristic elements in terms of the distribution of Zamiaceae in Colombia. These are a Choco Element, a montane element, a Rio Magdalena Valley element, and an Amazonian element.
A. CHOCO AND MONTANE ELEMENTS
Geographically, the Choco Element consists of the Choco, Valle de Cauca, Cauca, Narino, eastern through northeastern Antioquia, and southern Cordoba. Another way to view this is the western and northern lowland regions of the Cordillera Occidental to the Pacific Ocean. Within this area are an endemic genus, Chigua, with two species; three endemic species of Zamia, Z. amplifolia, Z. disodon, and Z. wallisii; and four species of Zamia, Z. china, Z. manicata, Z. obliqua, and Z. roezlii, with ranges that extend northward into Panama and southward into Ecuador. Two of these species, Z. disodon and Z. manicata, have counterparts east of the Andes. Zamia disodon is known from only two widely separated localities, one in Antioquia, Colombia, and the other in Huanuco, Peru (Stevenson, 2004). Currently these two populations are considered conspecific because of a paucity of collections, in particular reproductive material. The disjunct distribution of Z. disodon is paralleled by the occurrence of Z. manicata in Antioquia, Colombia, west of the Andes and the presence of its counterpart, Z. macrochiera, in a limited area of northeastern Peru (Stevenson, 2004). The close relationship of these two species is strongly supported by the presence of a gland-like collar at the juncture of the petiolule and the lamina, a feature found in no other cycad. Given the trans-Andean disjunct pattern of these two species and of Z. disodon, the fact that there is no known dispersal agent for neotropical cycads, and the antiquity of the cycads in the New World, as shown by the fossil record with Zamia present minimally in the Paleocene (Sabato, 1990; Stevenson & Artabe, 1999), I conclude that this distribution pattern is a result of a vicariant event related to the orogeny of the Andes, where once-widespread species have experienced extinction of intervening populations. Further support for this pattern comes from the distribution of Z. poeppigiana in Ecuador and Peru, where disjunct populations are found on both sides of the Andes (Stevenson, 2004), and from the occurrence of a few specimens from the Choco of Colombia that are here assigned to Z. amazonum, a species widely distributed throughout the Amazon Basin.
The montane element occurs in the northern Cordillera Occidental in Antioquia. There are two endemic, distinctive species of Zamia in this region whose populations are geographically near each other. Both of these species, Z. montana and Z. wallisii, were described by Alexander Braun in 1875, based upon material that was collected in 1873 by Gustav Wallis but that was subsequently lost (Sabato, 1990). Neither species was seen again until 1984 (Sabato, 1990). These two species truly grow in premontane to montane habitats at 1200-2000 m. These are the highest, cool, and wet habitats for any neotropical cycad. The origins of these two species remain enigmatic in the absence of phylogenetic analysis.
B. RIO MAGDALENA VALLEY ELEMENT
The Rio Magdalena Valley element consists of Zamia muricata, Z. lecointei, Z. poeppigiana, and the endemic Z. encephalartoides. Of these four species, Z. poeppigiana is limited to the southern part of the Rio Magdalena Valley, where it grows in wet forest habitats and where it represents a northern disjunct population in Colombia that is separated from the more widespread trans-Andean populations in Ecuador and Peru. In contrast, the other three species grow in very dry to arid habitats. Although the principal distribution of Z. lecointei is in the upper Amazon Basin, when present there it occurs in very sandy soils or on steep, rocky, very well drained, and dry soils. Zamia encephalartoides also occurs in very dry habitats and exhibits some morphological features, such as sclerophyllous leaflets with pungent apices, in common with Z. lecointei. These features are often associated with an arid environment and as such may be parallelisms, but they may also, with further analysis, indicate a close phylogenetic relationship between these two species.
Most collections of Zamia muricata from Colombia are from the Rio Magdalena Valley, but one collections is known also from Meta, on the eastern side of the Cordillera Oriental. The distribution of Zamia muricata is along coastal Venezuela, from Puerto Cabello west to coastal La Guajira, Colombia, and then southward along each side of the Cordillera Oriental. Basically, the known populations of Z. muricata in Santander, Boyaca, and Meta are disjunct from the coastal populations of this species; that is, there are no known intervening populations, although the intervening area has been explored botanically. Because there are no known dispersal agents for either Z. lecointei or Z. muricata, their presence on each side of the Cordillera Oriental is interpreted as a result of vicariance during the orogeny of the Cordillera Oriental.
C. AMAZONIAN ELEMENT
Four species, Zamia amazonum, Z. lecointei, Z. ulei, and Z. hymenophyllidia, occur principally east of the Cordillera Oriental and are considered here as an Amazonian element. The first three species are widespread in the Amazon Basin of Brazil, Venezuela, Colombia, and Peru. Two of them, Z. amazonum and Z. lecointei, each have single populations west of the Cordillera Oriental. As previously discussed, these are interpreted in terms of vicariance biogeography. It is interesting to note that Z. lecointei, which prefers dry habitats in the Amazon region, also occurs in a similar habitat outside that region. In the same manner, Z. amazonum prefers wet habitats in the Amazon region and also occurs in a similar situation in its disjunct population in the Choco of Colombia.
Zamia melanorrhachis has a wide distribution pattern in Colombia, ranging from Cordoba in the west to eastern Amazonas in the east. However, only four quite disjunct populations are known for this species. Zamia melanorrhachis appears to be related to Z. hymenophyllidia, because both species are unique in the cycads with the presence of extremely long, thin peduncles (to 30 cm long and 1-3 mm diam.), terminated by very small pollen cones (1-3 cm long and 1-3 mm diam.). Zamia hymenophyllidia is known from three collections in south-eastern Amazonas, Colombia, and one collection in contiguous Peru and thus is restricted to a small area of the upper Amazon. The single known population of Z. melanorrhachis in Amazonas, Colombia, occurs in the general vicinity of known populations of Z. hymenophyllidia. As discussed for other species of Zamia in Colombia with disjunct distributions but no known dispersal agent, this pattern of distribution is interpreted as vicariance pattern for Z. melanorrhachis, with Z. hymenophyllidia being a recently derived sister taxon. Phylogenetic analyses, coupled with continued collections of South American species of Zamia, should provide explicit tests of these hypotheses.
I offer my sincere gratitude to my cycad colleagues, without whose help this work would not have been possible. In particular, I would like to thank those who accompanied me in the field: Knut Norstog, Eric Norstog, the late Sergio Sabato, the late Padre Sergio Restrepoi, Jorge Brand, and Rodrigo Bernal. I also thank Rupert Barneby for help with Latin and Favio Gonzfilez for the Spanish version and his patience and encouragement, which led to completion of this work. I am deeply grateful to Amy Melson and Cynthia Armstrong for their excellent illustrations of the taxa included here. This work was made possible in part as a result of National Science Foundation Grants BSR-8607049 and BSR-8796279 awarded to the author.
VIII. Literature Cited
Audran, J. & E. Masure. 1977. Contribution a la connaissance de la composition des sporodermes chez les Cycadales (Prespermaphytes). Etude en microscopic electronique a transmission (M.E.T.) et a balayage. Palaeontographica 162: 115-158.
Braun, A. 1875. Die Frage nach der Gymnospermie der Cycadeen. Monatsber. k. Akad. Wiss. Berlin, 1875: 376-377.
Caputo, P., S. Cozzolino, L. Gaudio, A. Moretti & D. Stevenson. 1996. Karyology and phylogeny of some Mesoamerican species of Zamia(Zamiaceae). Amer. J. Bot. 83: 1513-1520.
Crepet, W. 1979. Insect pollination: A paleontological perspective. Bioscience 29: 102-108.
Crowson, R. H. 1991. The relations of Coleoptera to Cycadales. Pp. 13-28 in M. Zunino, X. Beltes & M. Blas (eds.), Advances in coleopterology, AEC, Barcelona.
Dammer, U. 1907. Cycadaceae. Verh. Bot. Vereins Brandenburg 47: 117-118.
Dehgan, B. & N. Dehgan. 1988. Comparative pollen morphology and taxonomic affinities in the Cycadales. Amer. J. Bot. 75: 1501-1516.
Ducke, A. 1915. Plantes nouvelles ou peu connues de la rdgion Amazonienne. Cycadaceae. Arch. Jard. Bot. Rio de Janeiro 1: 9-10, tab. 1.
--. 1922. Plantes nouvelles ou peu connues de la region Amazonienne (II Pattie). Cycadaceae. Arch. Jard. Bot. Rio de Janeiro 3: 20, tab. 1.
--. 1935. Plantes nouvelles ou peu connues de la region Amazonienne. Cycadaceae. Arch. Jard. Bot. Rio de Janeiro, ser. 8, 2: 27-28.
Fawcett, P. & K. Norstog. 1993. Zamia pumila in South Florida: A preliminary report on its pollinators R. slossoni, a snout weevil and P. zamiae, a clavicom beetle. Pp. 109-120 in D. W. Stevenson & K. J. Norstog (eds.), The biology, structure, and systematics of the Cycadales: Proceedings of CYCAD 90, the Second International Conference on Cycad Biology. Palm & Cycad Societies of Australia Cycads, Milton, Queensland, Australia.
--,--& A. Vovides. 1995. Pollination of two species of Zamia in South Florida and its implication for evolution of cycad strobili. Pp. 111-121 in D. D. Pant, D. D. Nautiyal, A. N. Bhatnagar, K. R. Surange, M. N. Bose & P. K. Khare (eds.), Proceedings of the International Conference on Global Environment and Diversification of Plants through Geological Time. South Asian Publishers, Allahabad, India.
Gao Z. & B. Thomas. 1989. A review of cycad megasporophylls with new evidence of Crossozamia Pomel and its associated leaves from the Lower Permian of Taiyuan, China. Rev. Paleobot. Palynol. 60: 205-223.
Gomez, L. 1982. Plantae Mesoamericanae Novae, IV. Phytologia 51: 473.
Hill, K. 1994. The Cycas rumphii complex (Cycadaceae) in New Guinea and the Western Pacific. Aust. Syst. Bot. 7: 543-567.
Jarvis, C., F. Barrie, D. Allan & J. Reveal. 1993. A list of Linnean generic names and their types. Regnum Veg. 127.
Marshall, J., N. Grobbelaar, J. Coetzee & R. Osborne. 1989. Pollen morphology of the Cycadales with special reference to the Encephalartos species. Pollen et Spores 31: 229-249.
Moretti, A. 1990a. Karyotypic data on North and Central American Zamiaceae (Cycadales) and their phylogenetic implications. Amer. J. Bot. 77: 1016-1029.
--. 1990b. Cytotaxonomy of the cycads. Mem. New York Bot. Gard. 57: 114-122.
-- & S. Sabato. 1984. Karyotype evolution by centromeric fission in Zamia (Cycadales). Pl. Syst. Evol. 146: 215-223.
--, P. Caputo, L. Gaudio & D. Stevenson. 1991. Intraspecific chromosome variation in Zamia (Zamiaceae, Cycadales). Caryologia 44: 1-10.
--, --S. Cozzolino & L. Gaudio. 1993. Karyotypes of New World cycads. Pp. 263-269 in D. W. Stevenson & K. J. Norstog (eds.), The biology, structure, and systematics of the Cycadales: Proceedings of CYCAD 90, the Second International Conference on Cycad Biology. Palm & Cycad Societies of Australia Cycads, Milton, Queensland, Australia.
Norstog, K. 1980. Chromosome numbers in Zamia (Cycadales). Caryologia 33: 419-428.
--. 1981. Karyotypes of Zamia chigua (Cycadales). Caryologia 34: 255-260.
--. 1986. Zamia chigua, a case of mistaken identity? Fairchild Trop. Gard. Bull. 41: 6-13.
-- & P. Fawcett. 1989. Insect-cycad symbiosis and its relation to the pollination of Zamia furfuracea (Zamiaceae) by Rhopalotria mollis (Curculionidae). Amer. J. Bot. 76: 1380-1394.
-- & T. Nicholls. 1997. The biology of the cycads. Cornell Univ. Press, Ithaca, NY.
--, D. Stevenson & K. Niklas. 1986. The role of beetles in the pollination of Zamia furfuracea L. fil.(Zamiaceae). Biotropica 18: 300-306.
Oberprieler, R. 1995a. The weevils (Coleoptera: Curculionoidea) associated with cycads, 1. Classification, relationships, and biology. Pp. 295-334 in P. Vorster (ed.), Proceedings of the Third International Conference on Cycad Biology, Cycad Society of South Africa, Stellenbosch.
--. 1995b. The weevils (Coleoptera: Curculionoidea) associated with cycads, 2. Host specificity and implications for cycad taxonomy. Pp. 335-378 in P. Vorster (ed.), Proceedings of the Third International Conference on Cycad Biology, Cycad Society of South Africa, Stellenbosch.
Osborne, R., D. Stevenson & K. Hill. 1999. The world list of cycads. Pp. 224-239 in C.-J. Chert (ed.), Biology and conservation of cycads: Proceedings of the Fourth International Conference on Cycad Biology, held in Panzhihua, Sichuan, China, 1-5 May 1996. International Academic Publishers, Beijing.
Pellmyr, O, W. Tang, I. Groth, G. Bergstrom & L. B. Thien. 1991. Cycad cone and angiosperm floral volatiles: Inferences for the evolution of insect pollination. Biochem. Syst. Ecol.19: 623-627.
Regel, E. 1876. Die Cycadeen, deren Gattungen und Arten. Gartenflora 25: 140-144.
Rumphius, G. 1741. Herb. Amboinensis 1: 86. t. 22, 23.
Sabato, S. 1990. West Indian and South American cycads. Mem. New York Bot. Gard. 57: 173-185.
Sacks, O. 1996. The island of the colour-blind. Macmillan, London.
Schultes, R. 1953. Notes on Zamia in the Colombian Amazon. Mutisia 15: 1-6.
--. 1958. Plantae Austro-Americanae, X. Cycadaceae. Bot. Mus. Leafl. Harvard Univ. 18: 114-115.
Schuster, J. 1932. Cycadaceae. Pp. 99(4,1): 1-168 in A. Engler (ed.), Das Pflanzenreich. W. Engelmann, Leipzig
Stevenson, D. 1980a. Observations on root and stem contraction in cycads (Cycadales) with special reference to Zamiapumila L. Bot. J. Linn. Soc. 81: 275-281.
--. 1980b. Radial growth in the Cycadales. Amer. J. Bot. 465-475.
--. 1981. Observations on ptyxis, phenology, and trichomes in the Cycadales and their systematic implications. Amer. J. Bot. 68: 1104-1114.
--. 1988. Strobilar ontogeny in the Cycadales. Pp. 205-244 in P. Leins, S. Tucker & P. Endress (eds.), Aspects of floral development. J. Cramer, Berlin.
--. 1990a. Morphology and systematics of the Cycadales. Mem. New York Bot. Gard. 57: 8-55.
--. 1990b. Chigua, a new genus in the Zamiaceae with comments on its biogeographic significance. Mem. New York Bot. Gard. 57: 167-172.
--. 1990c. Introduction. Mem. New York Bot. Gard. 57: vi-vii.
--. 1991. Zamiaceae. Flora of the Guianas. Ser. A, Fasc. 9: 7-11.
--. 1992. A formal classification of the extant cycads. Brittonia 44: 220-223.
--. 1993. The Zamiaceae in Panama with comments on phytogeography and species relationships. Brittonia 45: 1-16.
--. 2001. Cycadales. Flora de Colombia 21: 1-92.
--. 2004. Zamiaceae of Bolivia, Ecuador, and Peru. Pp. 173-194 in T. Waiters & R. Osborne (eds.), Cycad classification: Concepts and recommendations. CABI Publishing, Oxford.
-- & A. Artabe. 1999. Fossil Cycadales of Argentina. Bot. Rev. 65: 219-238.
-- & S. Sabato. 1986. Typification of names in Zamia L. and Aulacophyllum Regel (Zamiaceae). Taxon 35: 134-143.
-- & G. Siniscalco Gigliano. 1989. The systematic value of the monosaccharide composition and distribution pattern of cycad mucilages. Biochem. Syst. Ecol. 17: 185-190.
--, K. Norstog & D. Molsen. 1996. Midribs of cycad pinnae. Brittonia 48: 67-74.
--, --& P. Fawcett. 1998. Pollination biology of cycads. Pp. 277-294 in P. Rudall & S. Owens (eds.), International Conference on Plant Reproductive Biology. Royal Botanic Gardens, Kew.
Tang, W. 1987a. Insect pollination in the cycad Zamia pumila (Zamiaceae). Amer. J. Bot. 74: 90-99.
--. 1987b. Heat production in cycad cones. Bot. Gaz. 148: 165-174.
--. 1993. Heat and odour production in cycad cones and their role in insect pollination. Pp. 140-147 in D. W. Stevenson & K. J. Norstog (eds.), The biology, structure, and systematics of the Cycadales: Proceedings of CYCAD 90, the Second International Conference on Cycad Biology. Palm & Cycad Societies of Australia Cycads, Milton, Queensland, Australia.
Vovides, A. 1991. Insect symbionts of some Mexican cycads. Biotropica 23: 102-104.
--, K. Norstog, P. Fawcett, M. Duncan, R. Nash & D. Molsen. 1993. Histological changes during maturation in male and female cones of Zamia furfuracea L. fil.(Zamiaceae, Cycadales) and their significance in relation to pollination biology. Bot. J. Linn. Soc. 111: 241-252.
Walter, K. & H. Gillett (eds.). 1998. 1997 IUCN Red list of threatened plants. IUCN--The World Conservation Unit, Gland, Switzerland.
DENNIS WM. STEVENSON
New York Botanical Garden
Bronx, NY 10458, U.S.A.
|Printer friendly Cite/link Email Feedback|
|Author:||Stevenson, Dennis Wm.|
|Publication:||The Botanical Review|
|Date:||Apr 1, 2004|
|Previous Article:||The genus Cycas (Cycadaceae) in Vietnam.|
|Next Article:||Range and variation in the genus Ceratozamia (Zamiaceae).|