Gymnosperms of southeast Alabama.
Gymnosperms of southeast Alabama are represented by two families, five genera, 12 specific and four infraspecific taxa. Pinus is represented by eight taxa. Taxodium and Juniperus are each represented by two taxa. Chamaecyparis and Cunninghamia are represented by one taxon each. The area delineated as southeast Alabama includes Barbour, Butler, Coffee, Conecuh, Covington, Crenshaw, Dale, Escambia, Geneva, Henry, Houston, and Pike counties. Dichotomous keys and descriptions are based upon material deposited in the herbarium of Troy University (TROY). Distribution records are based upon specimens deposited in the Troy University Herbarium (TROY), Auburn University Herbarium (AUA), and The University of Alabama Herbarium (UNA).
Gymnosperms (literally, "naked seed") are a group of vascular plants whose seeds are not enclosed by a ripened ovary (fruit). The gymnosperms in the United States include 20 genera and 115 species (Flora of North America, 1993a).
Most classification systems today separate the extant gymnosperms into four distinct divisions: Coniferophyta, Cycadophyta, Ginkgophyta, and Gnetophyta (Flora of North America, 1993b). Of these, only the Pinophyta (Coniferophyta) contains native or naturalized taxa in Alabama. The Pinaceae and Cupressaceae are the only families in the Pinophyta with representatives in the state (Flora of North America, 1993a).
In the Pinaceae, eight species, all in the genus Pinus, are represented in southeast Alabama. All eight taxa are placed in the subgenus Pinus, Section Trifoliis, Subsection Australes (Price et al., 1998). Subgenus Pinus, known commonly as the "typical" or "hard pines", is characteristized by having the umbo dorsal and cone scales with a sealing band adjacent to the apophysis where the scales meet on the closed cone. The wing of the seeds are articulate, easily separated from the seed, to weakly adnate, not easily separated. The fascicles have 2-6 leaves and the sheaths are mostly persistent. Vascular bundles of the leaves are doubled and the stomata more or less equally distributed on all surfaces (Richardson, 1998).
In the Cupressaceae, four genera, Chamaecyparis, Cunninghamia, Juniperus and Taxodium, are represented in southeast Alabama. All four genera have seed cones in which the bract-scale complexes are fused for most of their common length. The seeds, 1-5 per scale, are wingless in Juniperus and Taxodium but consist of two narrow, lateral wings in Chamaecyparis and Cunninghamia (Eckenwalder, 1976; Flora of North America, 1993a).
Since 1961, three studies have addressed the gymnosperms of Alabama. Trees and Shrubs in the Heart of Dixie (Dean, 1961) provides excellent illustrations and general information on the gymnosperms. It does not, however, contain keys, and the distribution of each taxon in the state is incomplete. Alabama Trees (Davis and Davis, 1963) includes dichotomous keys, illustrations and descriptions. The distribution data is general, and the taxonomy, in many cases, is outdated. Clark (1971), in The Woody Plants of Alabama produced the most comprehensive and detailed work on gymnosperms of the state. Although illustrations are not included, the dichotomous keys and county distribution maps are useful. Since these publications are over 30 yr old, additional records are needed to adequately document the diversity and distribution of gymnosperms found in southeast Alabama. Spaulding et al. (2002) recognized the need for a more current gymnosperm flora and published Gymnosperms of Northeast Alabama and Adjacent Highlands.
The objectives of this study included the development of dichotomous keys and county distribution maps for the gymnosperms of southeast Alabama.
DESCRIPTION OF STUDY AREA
The area delineated as southeast Alabama includes Barbour, Butler, Coffee, Conecuh, Covington, Crenshaw, Dale, Escambia, Geneva, Henry, Houston, and Pike counties (Fig. 1). The entire study area lies within the Coastal Plain Province and has an area of 2 664 849 ha. The northeast corner of Butler County and the northern sections of Crenshaw, Pike and Barbour counties are in the Blue Marl Region. Most of the central section of the study area occurs in the eastern and western portions of the Southern Red Hills. Houston County and parts of Geneva and Covington counties in the southeast section of the study area are in the Lime-Sink Region. The southwest section of the study area occurs primarily in the Southwestern Pine Hills. One exception is a small region of central and southeastern Conecuh County, which is located in the Lime Hills (Harper, 1943).
The topography of the study area ranges from low rolling hills in the north to flat or gentle sloping ridges in the south. Three major watersheds drain the study area. From east to west they include the Chattahoochee. Pea/Choctawhatchee, and the Conecuh (Mettee et al., 1996).
The warm-temperate, moist climate of the study area has an average growing season ranging from 240 to 250 days. The Gulf of Mexico has a regulating effect on the climate and helps keep the temperature extremes at a minimum. The average annual temperature is approximately 20[degrees]C. Average temperatures during January, the coldest month, are 10.5[degrees]C, while July, the warmest month, averages 26[degrees]C. Precipitation ranges from 132 cm to 142 cm throughout most of the study area. The exception occurs in the southwestern section of the study area (Conecuh and Escambia counties) where the average ranges from 142 cm to 162 cm (Cartographic Research Laboratory, 2004).
MATERIALS AND METHODS
This treatment includes all taxa of gymnosperms known to occur naturally and those that have become established and are reproducing in southeast Alabama. The dichotomous keys and descriptions are based upon material deposited in the herbarium of Troy University (TROY). Distribution records are based upon specimens deposited in the Troy University Herbarium (TROY), Auburn University Herbarium (AUA), and The University of Alabama Herbarium (UNA). Additional distribution data was obtained from Clark (1971). Nomenclature follows Flora of North America (1993).
The gymnosperms of southeast Alabama were found to be represented by two families, five genera, 12 specific and four infraspecific taxa. The largest family, Pinaceae, is represented by one genus, Pinus, and eight specific taxa. Of the eight species, only one, P. virginiana Miller, is non-native to the study area. The other family, Cupressaceae, is represented by four genera, four specific and two infraspecific taxa. All members of this family are native to the study area except for Cunninghamia lanceolata (Lambert) Hooker, which is native to SE Asia.
KEY TO GYMNOSPERM FAMILIES</p> <pre> 1. Photosynthetic leaves needlelike, in fascicles of 1. Pinaceae 2-4 1. Photosynthetic leaves scalelike or needlelike, 2. Cupressaceae afasciculate </pre> <p>1. PINACEAE Lindley
PINUS Linnaeus *Pines*
Evergreen trees; leaves dimorphic, scale leaves short, on current year's growth only, needle leaves in bundles of 2-4, persisting 2-12 years; pollen cones, elongated, non-woody, short lived; ovulate cones conic or cylindrical, woody, persistent for two to many years; seeds with a single wing.</p> <pre> 1. Needles in bundles of 2
2 1. Needles in bundles of 2-3(4)
5 2. Bark of three year old twigs rough, exfoliatin 3 2. Bark of three year old twigs smooth, not 4 exfoliating 3. Needles in bundles of 2, <7 cm long, strongly 1. P. virginiana
twisted; buds red-brown 3. Needles in bundles of 2-3, >7 cm long, straight to 2. P. echinata slightly twisted; buds gray 4. Needles not twisted; tips of seed cone scales 3. P. clausa with a conspicuous horizontal ridge, cones scale with well developed erect to curved spines, upper cone surface darker brown at tip
4. Needles twisted; tip of seed cone scales 4. P. glabra
without a horizontal ridge or faint ridge only, cone scales with short spines, early deciduous, upper cone surface uniform brown throughout 5. Needles >25 cm long, fascicular sheath >2 cm long; 5. P. palustris ovulate cones >15 cm long 5. Needles <25 cm long, fascicular sheath <2 cm long; 6 ovulate cones <15 cm long
6. Ovulate cones <6 cm long; seeds <6 mm long 7 6. Ovulate cones >6 cm long; seeds >6 mm long 8 7. Needles 7-13 cm long; seeds 4-6 mm long; wing <15 2. P. echinata mm long; upland, dry soils 7. Needles 15-25 cm long; seeds 3-4 mm long; wing >15 6. P. serotina mmlong; lowland, poorly drained soils 8. Needles in bundles of 2 and 3 on the same 7. P. elliottii tree; ovulate cones with pedicels 20-30 mm long 8. Needles in bundles of 3; ovulate cones sessile 8. P. taeda to pedicels <10 mm long </pre> <p>1. P. virginiana Miller -- VIRGINIA PINE. Figure 2. Occasionally planted and naturally reproducing along roadsides.
2. P. echinata Miller -- SHORTLEAF PINE. Figure 3. Common. Dry uplands.
3. P. clausa (Chapman ex Engelmann) Sargent -- SAND PINE. Figure 4. Occasionally planted and reproducing. Sandhills. Synonym: P. inops Aiton var. clausa Chapman ex Engelmann; P. clausa var. immuginata Ward.
4. P. glabra Walter -- SPRUCE PINE. Figure 5. Common, though normally scattered and pure stands are rare. Mesic woodlands, floodplains.
5. P. palustris Miller -- LONGLEAF PINE. Figure 6. Common. Flatwoods, xeric clay hills, dry sandy uplands and sandhills. Synonym: P. australis F. Michaux.
6. P. serotina Michaux -- POND PINE. Figure 7. Scattered. Floodplains, swamp borders and bogs. Synonym: P. rigida Miller subsp. serotina (Michaux) R.T. Clausen; P. rigida var. serotina (Michaux) Hoopes.
7. P. elliottii Engelmann -- SLASH PINE. Figure 8. Common, often planted in pure stands. Lowlands to upland woodlands, old fields. Synonym: P. heterophylla (Elliott) Sudworth; P. taeda Linnaeus var. heterophylla Elliott.
8. P. taeda Linnaeus -- LOBLOLLY PINE. Figure 9. Common, often planted in pure stands. Mesic woods, swamp borders to dry uplands.
2. CUPRESSACEAE Bartlett
Evergreen shrubs or small trees; leaves four-ranked, opposite or whorled, needlelike or scalelike, 1-70 mm long; pollen cones terminal, spherical to oblong, simple (terminal panicles in Taxodium), solitary (rarely in clusters of 2-5); ovulate cones 3-50 mm long, berrylike or woody; seeds not winged or with 1-3 symmetrical or asymmetrical wings.</p> <pre> 1. Leaves >2.5 cm long; ovulate cone with leathery, 1. Cunninghamia
imbricate scales 1. Leaves <2.5 cm long; ovulate cones fleshy or with 2 woody, valvate scales 2. Leaves alternate, needlelike, deciduous; 2. Taxodium ovulate cones woody 2. Leaves opposited or whorled, scalelike to 3 subulate, evergreen; ovulate cones fleshy 3. Stems four-angles in cross section; branchlets
3. Juniperus erect to pendulous; ovulate cones without scales,
blue black to brownish blue, resinous 3. Stems flat in cross section; branchlets flattened, 4. Chamaecyparis fan-shaped; ovulate cones with scales, bluish purple to reddish brown, aresinous </pre> <p>1. CUNNINGHAMIA R. Brown *Chinese Fir*
Evergreen trees, monoecious; leaves spirally arranged, sessile, lanceolate or linearlanceolate, serrulate, 3-7 cm long; pollen cones narrowly oblong in 1-5 terminal fascicles, each with 8-20 cones; ovulate cones globose, ovoid, or cylindric-ovoid, 3-5 cm long and wide, scales sessile, imbricate, leathery; seeds flat, with 2 narrow, lateral wings.
1. Cunninghamia lanceolata (Lambert) Hooker -- CHINESE FIR. Figure 10. Rare, escaped from cultivation in Henry County. Well drained soil along roadside. A monotypic genus native to SE Asia (Bailey, 1924). Synonym: C. sinensis R. Brown ex Richard & A. Richard; Pinus lanceolata Lambert.
2. TAXODIUM Richard *Cypress*
Deciduous trees; pneumatophores normally present; leaves two-ranked on short shoots, alternate, linear to linear-lanceolate, flattened, 3-17 mm long; pollen cones globose in pendent axillary racemes or panicles; ovulate cones 20-50 mm in diameter, subglobose, 5-10 scales, valvate, thin and woody; seeds trigonous, wingless.
2. T. distichum (Linnaeus) Richard -- BALD CYPRESS. Two varieties grow in the study area.
2a. T. distichum var. distichum -- BALD CYPRESS. Figure 11. Short shoots pendent to horizontally spreading; leaves linear, 5-17 mm long, spreading, free portion contracted and basally twisted; pneumatophores with acute apex. Common. Swamps, floodplains, rivers, ponds and lake shorelines.
2b. T. distichum var. imbricarium (Nuttall) Croom -- POND CYPRESS. Figure 12. Short shoots ascending; leaves lanceolate, 3-10 mm long, appressed and overlapping, free portion not contracted and basally twisted; pneumatophores with obtuse apex. Uncommon but scattered throughout the southern portions of the study area. Sinks and wet, poorly drained depressions. Synonym: T. distichum var. nutans (Aiton) Sweet; T. ascendens Brongniart.
3. JUNIPERUS Linnaeus *Cedar*
Dioecious trees; juvenile leaves 3-6 mm long, sharp pointed, entire, adult leaves appressed, scalelike, overlapping, 1-3 mm long, entire; pollen cones terminal, single, 3-5 mm long, consisting of 3-7 sporophylls; ovulate cones berrylike, pedunculate, globose to subglobose, 3-9 mm long; seeds 1-2, rarely 3 or 4, per cone, 1.5-4.0 mm long.
3. J. virginiana Linnaeus -- RED CEDAR. Figure 13. Two varieties grow in the study area.
3a. J. virginiana var. virginiana -- EASTERN RED CEDAR. Figure 13a. Ovulate cones 4-6 (-7) mm; crown narrowly erect to conic or round; scale leaves acute at apex; pollen cones 3-4 mm. Common. Well drained mesic to xeric woods, fields, fencerows. More common on basic soils. Synonym: J. virginiana var. crebra Fernald & Griscom; Sabina virginiana (Linnaeus) Antoine.
3b. J. virginiana var. silicicola (Small) E. Murray -- SOUTHERN RED CEDAR. Figure 13b. Ovulate cones 3-4 mm; crown flattened; scale leaves bluntly obtuse to acute at apex; male cones 4-5 mm. Rare. Sand dunes, river sandbanks, xeric woods. Synonym: J. silicicola (Small) L.H. Bailey; Sabina silicicola Small.
4. CHAMAECYPARIS Spach * White Cedar*
Dioecious trees; leaves 1.5-3.0 mm long, entire, glandular abaxially; pollen cones terminal, single, 1-2 mm long, consisting of 2-4 opposite sporophylls; ovulate cones woody, 5-9 mm broad, 5-7 scales; seeds winged, 1-2 per fertile scale, 2-3 mm long.
4. C. thyoides (Linnaeus) Britton, Sterns & Poggenburg -- ATLANTIC WHITE CEDAR. Figure 14. Rare. Swamps and floodplains. Synonym: C. henryae H.L. Li; C. thyoides subsp. henryae (H.L. Li) E. Murray; C. thyoides var. henryae (H.L. Li) Little; Cupressus thyoides Linnaeus.
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We would like to thank the curators of herbaria at Auburn University (AUA) and The University of Alabama (UNA) for providing useful information during this study and making us welcome during our visits. The first author would like to thank the Troy University Faculty Development Committee for awarding a Summer Research Grant to support this project.
Bailey, L. H. 1924. Manual of cultivated plants. The MacMillan Co., New York, New York, USA.
Cartographic Research Laboratory. 2004. Climate Maps of Alabama. URL: http://alabamamaps.ua.edu/alabama/climate/index.html.
Clark, R. C. 1971. The woody plants of Alabama. Annals of the Missouri Botanical Garden. 58: 99-242.
Dean, B. E. 1961. Trees and shrubs in the Heart of Dixie. Coxe Publishing Co., Birmingham, Alabama, USA.
Davis, D. E., and N. D. Davis. 1963. Alabama trees. Auburn Experimental Station, Auburn, Alabama, USA.
Eckenwalder, J. E. 1976. Re-evaluation of Cupressaceae and Taxodiaceae: A proposed merger. Madrono 23: 237-256.
Flora of North America Editorial Committee (eds.). 1993a. Flora of North America North of Mexico, vol. 2. Pteridophytes and gymnosperms. Oxford University Press, New York, New York, USA.
Flora of North America Editorial Committee (eds.). 1993b. Flora of North America North of Mexico, vol. 1. Introduction. Oxford University Press, New York, New York, USA.
Harper, R. M. 1943. Forests of Alabama. Alabama Geological Survey Monograph. 10: 1-230.
Mettee, M. F., P. E. O'Neil, and J. M. Pierson. 1996. Fishes of Alabama and Mobile Basin. Oxmoor House, Birmingham, Alabama, USA.
Price, R. A., A. Liston, and S. H. Strauss. 1998. Phylogeny and systematics of Pinus. P.49-68. In: Ecology and Biogeography of Pinus. Richardson, D. M. (ed.). Cambridge University Press, New York, New York, USA.
Richardson, D. M. (ed.). 1998. Ecology and biogeography of Pinus. Cambridge University Press, New York, New York, USA.
Spaulding, D. D., J. M. Ballard, and R. D. Whetstone. 2002. Gymnosperms of northeast Alabama and adjacent highlands. Alabama Academy of Science Journal. 73: 38-54.
Michael Woods and Alvin R. Diamond. Jr.
Department of Biological and Environmental Sciences
Troy, Alabama 36082
Anniston Museum of Natural History
Anniston, Alabama 36202
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|Author:||Woods, Michael; Diamond, Alvin R., Jr.|
|Publication:||Journal of the Alabama Academy of Science|
|Date:||Jul 1, 2005|
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