Alcantarea lanceopetala Leme, 2014

Leme, Elton M. C., Till, Walter, Kollmann, Ludovic J. C., De Moura, Ricardo L. & Ribeiro, Otávio B. C., 2014, Miscellaneous New Species of Brazilian Bromeliaceae, Phytotaxa 177 (2), pp. 61-100 : 69-72

Alcantarea lanceopetala Leme , sp. nov. ( Figs. 5 , 6 )

This new species, when compared to the closest relative Alcantarea glaziouana , is characterized by the fewer number of leaves per rosette (ca. 15 vs. ca. 50), greenish primary bracts about equaling the stipes (vs. reddish to red, the basal ones distinctly exceeding the stipes), larger floral bracts (40–45 × 40–47 mm vs. (25–) 30–40 × (25–) 30–37 mm), longer sepals (39–40 mm vs. 30–35 mm), lanceolate petals (vs. sublinear) which are broader (22–23 mm vs. 9–13 mm) and having comparatively shorter basal appendages (10–15 mm vs. 15–25 mm), and the sulcus of the pollen with indistinct margins (vs. sharply cut margins) and completely covered by exine elements (vs. without exine elements).

Type: BRAZIL. Minas Gerais: Itaipé, Fazenda Santa Rosa, Pedra de Santa Rosa , 1010 m elevation, 17º19’24.23”S 41º39’13.63”W, 26 January 2014, R . Vasconcelos s.n., cult. E . Leme 8829 (holotype RB!, isotype HB!) .

Plants rupicolous, stemless, flowering ca. 180 cm high. Leaves ca. 15 in number, rosulate, coriaceous, forming a funnelform rosette; sheaths broadly elliptic-ovate, ca. 25 × 19 cm, subdensely and inconspicuously brown lepidote, whitish near the base, pale green toward the apex; blades narrowly sublinear-lanceolate, not narrowed at the base, 90–110 × 10–11 cm, green, inconspicuously and sparsely lepidote adaxially to glabrous, nerved, canaliculate near the base and nearly flat toward the apex, forming an angle of 45° with the main axis to nearly erect, apex acuminatecaudate. Peduncle ca. 75 cm long, 2.2–2.5 cm in diameter, erect, glabrous, green; peduncle bracts subfoliaceous, narrowly lanceolate, long acuminate, exceeding the internodes, exposing the peduncle, arcuate-recurved, greenish, flat toward the apex. Inflorescence paniculate, once branched, ca. 60 cm long (including the terminal branch), 30–45 cm in diameter, erect; main axis slightly flexuous, greenish, glabrous, ca. 2.2 cm in diameter at the base and ca. 1.2 cm in diameter at the distal end, internodes 3–5 cm long; primary bracts ovate-lanceolate and long acuminate (basal ones) to broadly ovate and shortly acuminate (apical ones), recurved at the apex, about equaling the stipes, with some water-holding capacity, glabrescent, greenish; branches ca. 12 in number (including the terminal one), 3–5 cm apart, 23–30 cm long, subspreading except for the slightly ascending apex, densely flowered before and at anthesis, with 20–24 flowers; rachis geniculate, slightly if at all angulose, glabrous, greenish, internodes 5–10 x 4–10 mm; stipes 3–10 × 1 cm, slightly complanate, greenish, glabrous, bearing 1–2 sterile bracts at the distal end except for the naked apical ones; the terminal branch similar to the lateral ones, shortly stipitate; floral bracts suborbicular, 40–45 × 40–47 mm, apex rounded to obtuse and slightly emarginate, concave, mainly the upper ones slightly inflated before anthesis, glabrous or nearly so, reaching ca. 3/4 of the sepals length, ecarinate, subcoriaceous except for the thinner margins. Flowers distichous, divergent, not secund at anthesis to slightly upwardly secund afterward, strongly fragrant, 10–11 cm long (with extended petals); pedicel 10–12 × 7–10 mm, subtrapeziform, greenish, glabrous; sepals symmetric, obovate, apex subrounded, 39–40 × 20–22 mm, glabrous, free, ecarinate, yellowish-white, distinctly cymbiform, thin coriaceous; petals narrowly obovate-lanceolate, apex narrowly rounded, 88–90 × 22–23 mm, white, strongly recurved to slightly spirally recurved at anthesis, completely exposing the stamens, becoming pendent-flaccidescent afterwards, bearing 2 appendages at the base; appendages sublinear, obtuse to apiculate, irregularly cucullate, 10–15 × 2.5–3 mm, adnate to the petals for 7–8 mm; stamens completely exposed at anthesis, straight or nearly so, distinctly shorter than the extended petals and exceeded by the stigma; filaments subterete, white, free, sometimes bearing irregularly arranged callosities; anthers linear, 11–12 mm long, filiform at anthesis, dorsifixed near the base; pollen broadly ellipsoid, ca. 65 µm long, sulcate, sulcus with indistinct margins, completely covered by low exine elements, exine broadly reticulate, lumina subrounded, muri narrowed; style shorter than the extended petals, equaling to exceeding the stamens, white; stigma conduplicate-spreading, blades slightly contorted, densely papillose, white, ca. 2.5 mm long. Capsules unknown.

Distribution and habitat:–– Alcantarea lanceopetala was found as a typical rupicolous species of granitic outcrops of the Atlantic Forest domain, in the county of Itaipé, Minas Gerais state, ca. 1000 m elevation, far from the coast. It was observed forming densely grouped individuals exposed to direct sun light or sometimes in slightly shaded sites near the border of the shrubby vegetation, sharing its habitat with sparsely distributed specimens of A. cerosa Leme, Fontana & Ribeiro (2010a: 114) .

The information on A. lanceopetala is inadequate to make a direct, or indirect, assessment of its risk of extinction based on its known distribution and/or population status, being considered here a data-deficient species ( IUCN 2010).

Etymology:––The name of this new species is a reference to the unusual obovate-lanceolate shape of its petals, which are comparatively broad, a unique character in the genus not shared with any other known species.

Observations:––At first glance, the general vegetative aspect of A. lanceopetala is reminiscent of a member the A. extensa ( Smith 1943: 116) Grant (1995: 13) complex. However, the inflorescence characteristics, mainly the shape and color, indicate morphological affinity with A. glaziouana ( Lemaire 1867: 43) Leme (1997: 35) , which is an endemic species from coastal, low altitude areas of Rio de Janeiro state. This new species differs from the closest relative by a fewer number of leaves per rosette (ca. 15 vs. ca. 50), greenish primary bracts (vs. reddish to red), about equaling the stipes (vs. the basal ones distinctly exceeding the stipes), larger floral bracts (40–45 × 40–47 mm vs. (25–) 30–40 × (25–) 30–37 mm), longer sepals (39–40 mm vs. 30–35 mm), lanceolate petals (vs. sublinear), which are much broader (22–23 mm vs. 9–13 mm) and have comparatively shorter basal appendages (10–15 mm vs. 15–25 mm), and the sulcus of the pollen with indistinct margins and completely covered by low exine elements. The pollen features of A. lanceopetala are very unusual because the genus is usually characterized by sulcus with sharply cut margins, not at all covered by exine elements, as observed in A. glaziouana .

Figures

FIGURE 5. Alcantarea lanceopetala (Vasconcelos s.n.). A. Habit, showing two individuals of A. cerosa (top left) on the background. B. Details of the flower and stamens, highlighting the comparatively broad petals. C. Inflorescence.

FIGURE 6. Alcantarea lanceopetala (Vasconcelos s.n.). A. Apex of the leaf. B. Flower. C. Floral bract.D. Sepals. E. Petal with two basal appendages and a stamen. F. Shape and size variation of the petal appendages.