Notes on Alcantarea: a new medium-sized species and additions to A. roberto-kautskyi.
The inselbegs of the northeastern region of Minas Gerais State and the northwestern of Espirito Santo State shelter countless botanical novelties, as in the genus Alcantarea, where large populations can be seen from a distance. In most cases it is very hard to reach such localities due to the inaccessibility of the steep terrain and the breathtaking abysms. However, when it is possible to find the a way to the top of the mountains, in most cases new species can be discovered.
Two examples of species from these difficult sites are presented here: a new medium-sized Alcantarea from Minas Gerais and the unusual A. roberto-kautskyi Leme that is rarely seen in cultivation.
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Alcantarea vasconcelosiana Leme, sp. nov. Type: Brazil, Minas Gerais, Itabirinha de Mantena, Serra do Pitengo, Pedra da Baleia, saxicolous, ca. 1,000 m elev., 20 Nov. 2008, R. Vasconcelos Leitao s. n., cult. E. Leme 7650 (Holotype, HB. Isotype RB).
A A. nevaresii Leme, cui affinis, sed vaginis foliorum utrinque apicem versus atrocastaneis, laminis foliorum brevioribus et latioribus, bracteis scapi suberectis et totaliter rubris, inflorescentia breviore et densiore, stipitibus ramorum basalibus bractea singula ornatis, bracteis primariis orbicularibus obtusisque, bracteis floriferis per anthesin imbricatis et sepalis longioribus differt.
Plant saxicolous in herbaceous to shrubby vegetation, stemless or nearly so, flowering 80-90 cm high. Leaves 20 to 25 in number, densely rosulate, suberect, forming a funnelform rosette much narrowed at the base and broader above; sheaths suborbicular, ca. 15 x 16 cm, inconspicuously and minutely brown-lepidote, dark castaneous mainly toward the apex on both sides, strongly coriaceous; blades ligulate, slightly narrowed toward the apex, not narrowed at the base, 20-25 x 8.5-9.5 cm, strongly coriaceous, green, inconspicously and sparsely white-lepidote adaxially but appearing glabrous, abaxially glabrous, suberect, apex acute and apiculate to abruptly acuminate to shortly caudate, slightly recurved. Scape stout, 30-40 cm long, 1-1.2 cm in diameter, erect, glabrous, red; scape bracts the basal ones subfoliaceous, the upper ones orbicular or nearly so, acuminate to broadly acute and distinctly apiculate, suberect, its basal portion enfolding the scape and with distinct water-holding capacity, exceeding the internodes and the upper ones almost completely concealing the scape, 5.5-8 x 5-5.5 cm, red, glabrous, covered by a oleaginous substance. Inflorescence shortly paniculate, densely once branched, 12-20 cm long (including the terminal branch), 15-18 cm in diameter, erect, rachis stout, slightly flexuous, red, glabrous, 0.8-1 cm in diameter, internodes 1.5-3 cm long; primary bracts distinctly exceeding the stipes but shorter than the branches, with water-holding capacity, the basal ones resembling the upper scape bracts, the upper ones orbicular, apex obtuse and stoutly apiculate, 4-5.5 x 4-5 cm, suberect, strongly convex, glabrous outside, inconspicuously and sparsely white lepidote inside, red; branches 8 to 11 in number (including the terminal one), 1.5-3 cm apart, the lateral branches 8-11 cm long, suberect-spreading, densely flowered at anthesis at least toward the apex, 3 to 8-flowered, rachis geniculate, subterete, slightly if at all angulose, 7-10 x 4 mm, glabrous, green, stipes 25-40 x 6 mm, suberect, slightly complanate mainly toward the apex, light green, glabrous, the basal ones each bearing 1 sterile bract arranged at the apex of the stipes, red toward the apex, greenish-yellow near the base, sharply carinate, the upper ones naked, the terminal branch erect or nearly so, similar to the upper lateral branches, subsessile; floral bracts ovate to broadly ovate, 31-33 x 22-27 mm, apex subacute, incurved, greenish-yellow with reddish margins except for the reddish basal one, glabrous, almost completely enfolding the sepals and equaling 2/3 of their length, distinctly imbricate mainly at early anthesis, afterwards slightly if at all imbricate except for the basal ones, strongly convex, carinate. Flowers distichous, divergent, suberect, not secund, fragrant, densely arranged before anthesis and afterwards, 8.5-9.3 cm long (with extended petals including the stamens), distinctly fragrant, pedicels stout, ca. 9 x 7 mm, subcylindrical, green, glabrous; sepals slightly asymmetrical, subelliptic-obovate, apex subacute, 35-36 x 12-13 mm, glabrous, free, ecarinate, yellowish-green, thin in texture; petals sublinear, apex narrowly obtuse-cucullate, 81-82 x 7-8 mm, bright yellow, strongly recurved at anthesis, completely exposing the stamens, becoming pendent-flaccidescent afterwards, bearing at the base 2 linear, prevailingly acuminate, but sometimes subobtuse or bidentate, entire, ca. 22 x 2 mm appendages adnate to the petals for 18-19 mm, (the distal margins free, the proximal margins adnate to petals for 18-19 mm), the free lobes ovate, 3-4 mm long, apex slightly recurved; stamens completely exposed by the recurved petals at anthesis, suberect; filaments terete, white, the antesepalous ones free, the antepetalous ones shortly adnate to the petals; anthers linear, 7-8 mm long, base sagittate, apex obtuse, fixed near the base, shorter than the petals; pollen narrowly ellipsoid, sulcate, exine broadly reticulate, lumina rounded, muri narrowed; style exceeding the petals, white; stigma conduplicate, blades subspreading, densely papillose, white, ca. 1.5 mm long. Capsules unknown.
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The name chosen for this new species honors Reginaldo de Vasconcelos Leitao, a bromeliad and orchid enthusiast from Governador Valadares, Minas Gerais, who originally found this new species. Reginaldoss field investigations have brought to light many rare bromeliad species from the region where he lives.
Alcantarea vasconcelosiana is closely related to A. nevaresii, but can be distinguished from it by the leaf sheaths being dark castaneous on both sides and toward the apex (vs. pale colored), leaf blades shorter and broader (20-25 x 8.5-9.5 cm vs. ca. 55 x 7 cm), forming a more compact and robust rosette, scape bracts suberect and completely red (vs. suberect with distinctly recurved apex and green toward the apex), inflorescence distinctly shorter (12-20 cm vs. ca. 45 cm long) with branches densely arranged, basal branches bearing a single sterile bract (vs. ebracteate), primary bracts orbicular and obtuse (vs. broadly ovate and acuminate), floral bracts imbricate at least at early anthesis (vs. not imbricate even in early anthesis), and by the longer sepals (35-36 mm vs. 30 mm long).
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This new species was found growing on inclined granitic surfaces covered by herbaceous to shrubby vegetation in inselbergs of the region of Itabirinha de Mantena, Minas Gerais State, where it forms sparsely distributed groups of plants. In contrast, its closest morphological relative, A. nevaresii, is a typical inhabitant of the mountains of Teresopolis and Nova Friburgo (Leme, 1995), where it forms quite large and dense populations.
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The other species, Alcantarea roberto-kautskyi, was originally discovered in the region of Baixo Guandu, Espirito Santo State, about 11 years ago (Leme, 1999). Since then, a pup descending from the type specimen was maintained in cultivation in Refugio dos Gravatas, Teresopolis, Rio de Janeiro, and finally flowered in November 2008, allowing additional observations mainly on its flower details, as indicated in the amended description presented below:
Alcantarea roberto-kautskyi Leme, Harvard Pap. Bot. 4 (1): 148, fig. 10. 1999. Inflorescence branches 21 to 30 in number (including the terminal one), stipes bearing 2 to 6 sterile bracts. Flowers odorless, anthesis nocturnal, ca. 14.5 cm long (including the extended petals); sepals narrowly obtuse to subacute; petals 10.5-13.2 x 1.5-1.7 cm, pale cream colored before anthesis, white and spirally recurved at anthesis, basal appendages 1.2-1.4 x 0.4-0.6 cm, thick and slightly rigid, lobes suborbicular, subspreading and obstructing the corolla, apex truncate-crenulate or irregularly dentate. stamens 11-13 cm long; anthers sublinear, 1.3-1.6 cm long, base distinctly sagittate, apex obtuse, dorsifixed at 2/5 of its length above the base, versatile and hanging upside down at anthesis, with the margins of the opposed pollen sacs only partially touching each other at anthesis and not completely clasping the connective area; pollen ellipsoidal, sulcate, exine broadly reticulate, lumina rounded, muri narrowed; stigma conduplicate-spiral, ellipsoidal-capitate, blades 0.4-0.5 cm long, densely papilose, white.
Alcantarea roberto-kautskyi is a large species, a typical inhabitant of inaccessible vertical rock walls, which explains why it is rarely seen in cultivation. The position of the inflorescence at an angle of ca. 90[degrees] in relation to the main axis of the plant suggests an adaptation to its preferable vertical rocky habitat, allowing branches to avoid touching the rocky walls and facilitating pollinator activities. It was recently identified from the county of Sao Roque do Canaa, Espirito Santo State (material deposited in MBML), broadening its known distribution area.
Besides the unusual general appearance of this species due to the leaves being densely covered by a dense layer of white epicuticular wax and the branches bearing long stipes with the bracts and flowers densely arranged on its distal portion, other striking characteristics now observed are related to anthers and stigma. While most Alcantarea species presents anthers dorsifixed near the base, rigidly fixed and following the same orientation of the filaments, with the margins of the opposed pollen sacs touching to slightly overlapping each other at anthesis and completely clasping the connective area (Leme, 2007), the anthers of A. roberto-kautskyi are versatile and dorsifixed at 2/5 of its length above the base, hanging loosely upside down at anthesis. The margins of the opposed pollen sacs only partially touch each other at anthesis, not completely clasping the connective area.
This anther characteristic now observed in Alcantarea may contribute to understanding the phylogeny of the group, as well as its pollination biology. According to D'Arcy (1996), versatile anther seems to have evolved in response to generalist flying animal pollinators (e. g., insects, birds, bats), but it can shift with little or no modification to anemophily. In some plants, rigidly fixed anthers may have evolved from versatile anthers as bees replaced generalist visitors, being versatile anthers commonly found in both monocots and dicots, in some basal taxonomic groups as well as many advanced ones (D'Arcy, 1996).
In addition, the stigma of A. roberto-kautskyi is conduplicate-spiral and ellipsoidalcapitate, but not bearing suberect to spreading blades as most congeners. All these features reinforce the suggested closer morphological proximity of Alcantarea to Tillandsia in an unclear extent (Leme, 2007). An example of very similar anthers and stigma morphology is T. viridiflora (Beer) Baker, the type species of Tillandsia subgenus Pseudalcantarea Mez, suggesting at least an equivalent pollination syndrome when compared to A. robertokautskyi. It is interesting to mention that in the investigation based on DNA sequence data conducted by Barfuss et al. (2005), T. viridiflora is sister to the rest of Tillandsia, Racinaea and Viridantha, despite this relationship has only weak bootstrap support.
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Based on the binomials accepted by Luther (2008) and the more recent additions, the genus Alcantarea currently includes 28 recognized species, as listed below:
Alcantarea benzingii Leme Alcantarea brasiliana (L. B. Sm.) J. R. Grant Alcantarea burle-marxii (Leme) J. R. Grant Alcantarea distractila Leme & Paula Alcantarea duarteana (L. B. Sm.) J. R. Grant Alcantarea edmundoi (Leme) J. R. Grant Alcantarea extensa (L. B. Sm.) J. R. Grant Alcantarea farneyi (Martinelli & A. F. Costa) J. R. Grant Alcantarea geniculata (Wawra) J. R. Grant Alcantarea glaziouana (Lem.) Leme Alcantarea hatschbachii (L. B. Sm. & Read) Leme Alcantarea heloisae J. R. Grant Alcantarea imperialis (Carriere) Harms Alcantarea longibracteata Leme & Fraga Alcantarea lurida Leme Alcantarea mucilaginosa Leme Alcantarea nahoumii (Leme) J. R. Grant Alcantarea nevaresii Leme Alcantarea nigripetala Leme & L. Kollmann Alcantarea odorata (Leme) J. R. Grant Alcantarea patriae Versieux & Wand. Alcantarea regina (Vell.) Harms Alcantarea roberto-kautskyi Leme Alcantarea simplicisticha Leme & A. P. Fontana Alcantarea tortuosa Versieux & Wand. Alcantarea turgida Versieux & Wand. Alcantarea vasconcelosiana Leme Alcantarea vinicolor (E. Pereira & Reitz) J. R. Grant
We thank Walter Till for reviewing the manuscript and for his valuable comments and suggestions.
Barfuss, M. H. J., R. Samuel, et al. (2005). "Phylogenetic relationships in subfamily Tillandsioideae (Bromeliaceae) based on DNA sequence data from seven plastid regions." Am. J. Bot. 92: 337-351.
D'Arcy, W. G. (1996). Anthers and stamens and what they do. The Anther--form, function and phylogeny. W. G. D'Arcy and R. C. Keating. Cambridge, U.K., Cambridge University Press: 1-24.
Leme, E. M. C. (1995). "Contribuicao ao estudo do genero Alcantarea - I/ Contribution to the study of the genus Alcantarea--I." Bromelia 2(3): 15-23.
Leme, E. M. C. (1999). "New Species of Brazilian Bromeliaceae: A Tribute to Lyman B. Smith." Harvard Papers Bot. 4(1): 135-168.
Leme, E. M. C. (2007). "Improving Taxa and Character Sampling to Support Generic Status of Alcantarea." J. Bromeliad Soc. 57(5): 208-215.
Luther, H. (2008). An alphabetical list of bromeliad binomials. Eleventh Edition. USA, Bromeliad Society International.
Elton M. C. Leme (1)
(1) Herbarium Bradeanum, Rio de Janeiro--RJ, Brazil email@example.com
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|Author:||Leme, Elton M.C.|
|Publication:||Journal of the Bromeliad Society|
|Date:||Jan 1, 2009|
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