Alcantarea acuminatifolia Leme, 2013

Leme, Elton M. C. & Kollmann, Ludovic J. C., 2013, Miscellaneous New species of Brazilian Bromeliaceae, Phytotaxa 108 (1), pp. 1-40 : 7-10

Alcantarea acuminatifolia Leme , sp. nov. ( Figs. 4 A–G , 5 A–E )

This new species differs from Alcantarea odorata by the longer and distinctly broader inflorescence, longer branches with higher number and laxly arranged flowers, longer floral bracts, flowers slightly perfumed, and by the petals being only recurved at anthesis.

Type: — BRAZIL. Minas Gerais: Além Paraíba, BR 116 , ca. 20 km from Além Paraíba, August 2001, C. C . Paula s.n., fl. cult. E. Leme 5368 (holotype HB!, isotype RB!) .

Plants rupicolous, flowering 240–260 cm high. Leaves ca. 40 in number, densely rosulate, suberect, forming a broadly funnelform rosette; sheaths elliptic-ovate, 17–19 × 11–11.5 cm, inconspicuously and minutely brown lepidote, greenish mainly toward the apex; blades sublinear, not narrowed at the base, 70–72 × 7 cm, coriaceous, inconspicously and sparsely white lepidote to glabrescent abaxially, green but the color partially obscured by a dense layer of white epicuticular wax on both sides, apex long acuminate-caudate, slightly recurved. Peduncle stout, 55–120 cm long, 25–30 mm in diameter, erect, covered by white wax, wine-reddish colored; peduncle bracts foliaceous to subfoliaceous, suberect with slightly recurved apex, many times longer than the internodes but not completely concealing the peduncle, densely covered by white epicuticular wax. Inflorescence paniculate, once branched, 150–165 cm long (including the terminal branch), 55–90 cm in diameter, erect; rachis stout, wine-reddish, covered by white wax, 10–25 mm in diameter; primary bracts densely covered by white epicuticular wax; the basal ones resembling the upper peduncle bracts but smaller, ovate-lanceolate, long acuminate-caudate with recurved apex, distinctly exceeding the stipes; the upper ones broadly ovate, acuminate to acute, distinctly shorter than the stipes; branches 35–40 in number (including the terminal one), 2.5–10 cm apart, 23–30 cm long (upper ones) to 35–50 cm long (basal ones), spreading, laxly flowered at anthesis and afterwards, 10–16-flowered; stipes 5–16 × 0.4–0.6 cm, terete, green to reddish near the base, glabrous, bearing 1 (upper ones) to 3 (basal ones) sterile bracts shorter than the internodes and arranged near the apex of the stipes, obtusely if at all carinate, stramineous; rachis flexuous to geniculate, subterete, slightly if at all angulose; internodes 1.5–4 × 0.2–0.5 cm, glabrous, green; the terminal branch erect at the base and turning arcuate toward the apex, ca. 25 cm long, ca. 15-flowered, with a ebracteate, ca. 2 cm long stipe; floral bracts broadly elliptic, 27–30 × 25–27 mm, apex rounded to obtuse, yellow except for the greenish margins, turning yellowish-castaneous after anthesis, glabrous, almost completely enfolding the sepals and equaling 1/2 of their length, convex, distinctly nerved mainly after anthesis, ecarinate. Flowers distichous, divergent, suberect, not secund, slightly fragrant, laxly arranged at anthesis, ca. 10.3 cm long (with extended petals and including the stamens); pedicels stout, ca. 12 mm long, 8–9 mm in diameter at distal end, green, glabrous; sepals narrowly obovate, apex obtuse to subacute, 35–38 × 18–19 mm, inconspicuously and sparsely brown lepidote adaxially, glabrous abaxially, free, ecarinate, green near the base and yellow toward the apex, thick-coriaceous near the base, thinly coriaceous toward the apex; petals linear or nearly so, apex narrowly obtuse-emarginate, ca. 93 × 8 mm, golden yellow, distinctly recurved at anthesis but not spiralescent, completely exposing the stamens, bearing at the base 2 sublinear appendages; appendages ca. 25 mm long, their free blades ovate, obtuse, entire, ca. 6 × 3 mm; stamens completely exposed by the recurved petals at anthesis, erect, distinctly shorter than the petals; filaments terete, whitish; anthers linear, ca. 12 mm long, base bilobed, apex obtuse, dorsifixed near the base; style slightly exceeding the petals, ca. 95 mm long, white; stigma conduplicate-patent, spreading-contorted, densely papillose, white, blades ca. 3 mm long. Capsules unknown.

Distribution and habitat:— Alcantarea acuminatifolia presents the typical habit for the genus. It grows as a rupicole on vertical granitic walls in the Atlantic Forest domain, in Minas Gerais state, about 20 km from the border with Rio de Janeiro State. It forms large and dense groups of plants completely exposed to sunlight, being quite abundant at the type locality, where it can be recognized even from a distance, due to its bulky appearance, the peculiar leaf-rosette and the well developed inflorescence.

Etymology:—The name of A. acuminatifolia is a reference to the acuminate apex of its leaf blades.

Additional specimen examined (paratype): –– BRAZIL. Minas Gerais: Além Paraíba, BR 116 , km 795, ca. 2 km after Rio Angu ( Leopoldina–Além Paraíba), 393 m elevation, 21° 42’ 48” S 42° 43’ 55” W, 23 June 2012, E. Leme 8600 & R. Oliveira ( RB) .

Observations:— Alcantarea acuminatifolia has been confused with its close relative, A. odorata ( Leme 1989:175) J.R. Grant (1995: 13) , due to the similar vegetative leaf rosette. However, when in bloom, it can be distinguished by the longer inflorescence (150–165 cm vs. 40–100 cm long), which is distinctly broader (55– 90 cm vs. 15–26 cm in diameter), longer first order branches (23–30 cm vs. 7–16 cm long) with a higher number of flowers (10–16 vs. 4–11), longer floral bracts (27–30 cm vs. 17–25 cm long), laxly arranged (vs. subdensely arranged) and weakly perfumed flowers (vs. strongly perfumed), and by the petals being only recurved at anthesis (vs. strongly spiralescent-recurved).

Figures

FIGURE 4. A–G. Alcantarea acuminatifolia (Paula s.n.). A. Population of A. acuminatifolia at the type locality. B. Rupicolous habit. C. Habit of flowering specimen in cultivation. D. Apical portion of the inflorescence. E. Basal branch. F. Basal branch of A. acuminatifolia (left) compared with a basal branch of A. odorata (right). G. Floral bract and flower of A. acuminatifolia (left) compared with floral bract and flower of A. odorata (right).

FIGURE 5. A–E. Alcantarea acuminatifolia (Paula s.n.). A. Apex of leaf blade. B. Floral bract. C. Floral bract and flower. D. Sepal. E. Petal with appendages and inner stamen. F–K. A. occulta (Leme et al. 8665). F. Apex of leaf blade. G. Floral bract. H. side view of the floral bract. I. Flower. J. Sepals. K. Petal with appendages and inner stamen. Scale bars = 1 cm.