Alcantarea occulta Leme, 2013

Leme, Elton M. C. & Kollmann, Ludovic J. C., 2013, Miscellaneous New species of Brazilian Bromeliaceae, Phytotaxa 108 (1), pp. 1-40 : 10-14

Alcantarea occulta Leme , sp. nov. ( Figs. 5 F–K , 6 A–G , 7 )

This new species differs from its relatives, Alcantarea compacta , A. duarteana , and A. vasconcelosiana by the distinctly taller size and much higher number of leaves forming a regular funnelform rosette with large considerable water holding capacity, the size and shape of the leaf blades, comparatively longer inflorescence, basal primary bracts exceeding to equaling the branches, the size and shape of floral bracts, the length of the sepals, the strongly perfumed flowers, and by the longer petal appendages.

Type: — BRAZIL. Minas Gerais: Alvarenga, near the border of Tarumirim, Córrego Alta Floresta , old property of Alcebíades , 1032 m elevation, 19º 24’ 29” S, 41º 46’ 17” W, 22 June 2012, E . Leme 8665, R . Vasconcelos & R . Oliveira (holotype RB!, isotype HB!) .

Plants terrestrial on quartzitic sand or sometimes rupicolous, flowering 120–180 cm high. Leaves 35–40 in number, densely rosulate, suberect, forming a funnelform rosette; sheaths broadly ovate, 17–18 × 12–13.5 cm, coriaceous, inconspicuously and minutely brown lepidote, pale castaneous toward the base and greenish toward the apex; blades narrowly triangular, 30–47 cm long, 5–6 cm wide at the base, coriaceous, canaliculate near the base and flat near the apex, inconspicuously and sparsely white lepidote adaxially to glabrescent, glabrous abaxially, green, apex long acuminate-caudate. Peduncle stout, 70–100 cm long, 15–18 mm in diameter, erect, glabrous, dark red; peduncle bracts the basal ones subfoliaceous; the upper ones glabrous, lustrous, with a suborbicular base, 4.5–5.5 × 5–5.3 cm, dark red, with distinct water holding capacity; blades narrowly triangular, 9–14 × 1.8–2.5 cm, dark red near the base and green toward the apex, spreading-recurved toward the apex, distinctly longer than the internodes but not concealing the peduncle, glabrous. Inflorescence shortly paniculate, once-branched, 25–55 cm long (including the terminal branch), 10–15 cm in diameter, erect, covered by an oleaginous substance; rachis stout, red, glabrous, straight or nearly so, 10–15 mm in diameter; primary bracts with distinct water holding capacity, glabrous, red, subspreading-recurved, the basal ones resembling the upper peduncle bracts, distinctly exceeding to equaling the branches; the upper ones broadly ovate to suborbicular, acuminate-caudate to acuminate, equaling to distinctly shorter than the branches, 4.5–8 × 3.8–4.5 cm; branches 11–20 in number (including the terminal one), 1–5 cm apart, 6–10 cm long, forming an internal angle of 30° with the main axis, densely flowered at anthesis and afterwards, 3–7- flowered; rachis flexuous, subterete; internodes 0.4–0.8 × 0.3–0.4 cm, glabrous, reddish to green; stipes 1–3 × 0.7–0.8 cm, slightly complanate, reddish to green, glabrous, naked or bearing 1 sterile bract at distal end of the stipe; bract carinate, green with reddish apex; the terminal branch inconspicuous; floral bracts broadly elliptic, apex obtuse, slightly incurved, 30–35 × 23–24 mm, green except the basal ones red near the apex, glabrous, lustrous, nerved, completely enfolding the sepals and nearly equaling them, strongly convex, distinctly carinate, thin in texture. Flowers distichous, divergent, not secund, distinctly fragrant, densely arranged at anthesis, 8–9 cm long (with extended petals and including the stamens); pedicels ca. 6 mm long, ca. 6 mm in diameter at distal end, green, glabrous; sepals narrowly obovate, apex rounded or nearly so, 28–29 × 10–12 mm, glabrous, free, ecarinate, green, slightly thickened near the base, thin in texture toward the apex; petals linear, apex narrowly obtuse, 73–80 × 7 mm, golden yellow before anthesis and paler yellow at anthesis, distinctly recurved to spiralescent at anthesis, completely exposing the stamens, bearing 2 linear appendages at the base; appendages 25–30 × 2 mm long, their free blades ovate to oblong, acute, irregularly bidentate or entire and obtuse, 5 × 1.5–2 mm; stamens erect or nearly so, distinctly shorter than the petals; filaments terete, whitish; anthers linear, 7–8 mm long, base bilobed, apex obtuse, dorsifixed near the base; style about as long as the petals, greenish; stigma conduplicate-patent, spreading-contorted, densely papillose, white, blades 1– 1.3 mm long. Capsules narrowly fusiform, acuminate, ca. 22 mm long, ca. 8 mm in diameter near the base, shorter than the sepals; seeds 10–13 mm long, basal umbrella-like, plumose micropylar coma 5–6 mm long, distinctly shorter than the straight, undivided apical chalazal appendage.

Distribution and habitat:— Alcantarea occulta is a terrestrial or sometimes rupicolous species, ranging from 900 to 1550 m elevation, in the counties of Alvarenga and Conselheiro Pena, Minas Gerais state. It was found in three different localities, two of them in Alvarenga, where populations with higher number of individuals were documented and cited here, and one population with a few specimens at Pico do Padre Angelo, the most elevated mountain in the region, in the neighboring county of Conselheiro Pena, without fertile collected specimen.

This new species usually lives partially hidden in shrubby and subshrubby vegetation of an intermediate physiognomy between altitude Atlantic Forest and Campos Rupestres. This is an unusual habitat condition for species of this genus, which is traditionally known for growing in open, well exposed rocky sites, and the terrestrial habit is supposed to occur only accidentally (Leme 2007). It grows as solitary individuals or forms small and dense clumps due to vegetative propagation by means of short axillary shoots. When sterile, A. occulta can hardly be spoted in the shrubby vegetation, but its comparatively tall and showy inflorescences usually equal or exceed the surrounding shrubs, making it visible from a distance in the blooming season.

Etymology:—The name chosen for this new species refers to its individuals that are more or less hidden in shrubby and subshrubby vegetation which is an unusual habitat for species of this genus.

Additional specimens examined (paratypes):–– BRAZIL. Minas Gerais: Alvarenga, near the border of Tarumirim, Córrego Alta Floresta, old property of Alcebíades, 967 m elevation, 19º 25’ 09” S, 41º 46’ 26” W, 22 June 2012, E . Leme 8661, R . Vasconcelos & R . Oliveira ( RB!); idem, Alvarenga, Pico da Aliança , 1440 m elevation, 19º 23’ 42” S, 41º 40’ 08” W, 12 October 2012, E . Leme 8709, R . Vasconcelos & R . Oliveira ( RB!) .

Observations:— Alcantarea occulta is closely related to A. compacta Leme & Ribeiro (2010: 259) . However, the new species can be easily distinguished by its taller size (120–180 cm vs. 60–80 cm high), the higher number of leaves (35–40 vs. 17–20 in number), narrowly triangular leaf blades (vs. subtriangularlanceolate), which are longer (30–47 cm vs. 15–24 cm long), comparatively longer inflorescence (25–55 cm vs. 22–30 cm long), primary bracts longer than to equaling the branches (vs. shorter than the branches), floral bracts broadly elliptic (vs. orbicular or nearly so), which are longer (30–35 mm vs. 20–27 mm long), strongly perfumed flowers (vs. slightly perfumed only) and by the longer petal appendages (25–30 mm vs. 10–17 mm long).

On the other hand, this new species can be also compared with A. duarteana (Smith 1968: 80) Grant (1995: 13) , differing by the higher number of leaves (35–40 vs. 15–17), forming a regular funnelform rosette with large water holding capacity (vs. very narrowly funnelform rosette with reduced water holding capacity), shorter leaf blades (30–47 cm vs. 60–70 cm long), inflorescence with higher number of branches (15–20 vs. 11–15), larger floral bracts (33–35 × 23–24 mm vs. ca. 25 × 21 mm), and by the pale yellow petals at anthesis (vs. golden yellow petals at anthesis) with longer basal appendages (25–30 vs. 20–22 mm long).

Finally, A. occulta is also closely related to A. vasconcelosiana Leme (2009: 20) , differing by the taller size when in bloom (120–180 cm vs. 80–90 cm tall), the higher number of leaves (35–40 vs. 20–25), narrowly triangular leaf blades (vs. lingulate), which are longer (30–47 cm vs. 20–25 cm) and narrower (5–6 cm vs. 8.5–9.5 cm wide), and have an acuminate-caudate apex (vs. acute and apiculate). In addition, this new species can be distinguished by the longer (25–55 cm vs. 12–20 cm long) and comparatively narrower inflorescence (10–15 cm vs. 15–18 cm in diameter), shorter sepals (28–29 mm vs. 35–36 mm long), and by the longer petal appendages (25–30 mm vs. ca. 22 mm long).

Despite being also considered an endemic species for Minas Gerais state, A. compacta and A. duarteana are inhabitants of typical Campos Rupestres vegetation of the Espinhaço Range, where they live as rupicoles in completely exposed environments, while A. occulta lives in the Atlantic Forest domain associated to shrubby and subshrubby vegetation, strongly influenced by elements of Campos Rupestres from the rock outcrops at the higher part of the mountains. This peculiar habitat is more similar to A. vasconcelosiana , despite that this species, like the remaining relatives, was often observed living in more exposed sites.

Figures

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.

FIGURE 6. A–G. Alcantarea occulta (Leme et al. 8665). A. Population at the type locality in initial flowering state. B. Habit. C. Landscape view from the region of the type locality, highlighting the Atlantic Forest on the lower parts of the hills; in the background Pico da Aliança, the highest mountain in the region. D. Population at the summit of Pico da Aliança. E. Details of the leaf rosette and basal peduncle bracts. F. Details of the basal branch and flower. G. Basal portion of the inflorescence.

FIGURE 7. Alcantarea occulta (Leme et al. 8709). A. Paratype specimen at Pico da Aliança.