Dyckia acutiflora Leme & Z.J.G. Miranda, 2012

Leme, Elton M. C., Ribeiro, Otávio B. C. & Miranda, Zenilton De J. G., 2012, New species of Dyckia (Bromeliaceae) from Brazil, Phytotaxa 67 (1), pp. 9-37 : 10-12

Dyckia acutiflora Leme & Z.J.G. Miranda , sp. nov. ( Figs. 1 , A–E, 2 , A–F)

This new species is characterized by the comparatively narrow and numerous leaves, inflorescence densely covered by white glandulose trichomes except for the glabrescent or glabrous petals, basal floral bracts narrow and equaling the petals, acute sepals and petals, and by the free filaments above the common tube with the petals. The presence of glandulose trichomes and the shape of the sepals and petals distinguish it from Dyckia remotiflora .

Type:— BRAZIL. Goiás: Santo Antonio do Descoberto , Paraiso das Cascatas, Z . Miranda s.n., February 2006, cultivated, E . Leme 6806 (holotype RB!) .

Plants terrestrial, flowering 90–100 cm high. Leaves ca. 45 in number, densely rosulate, thinly coriaceous; sheaths broader than the blades; blades narrowly triangular, nearly flat, arcuate, 25–30 cm long, 1.1–1.4 cm wide at the base, ca. 1 mm thick near the base, yellowish-green, nerved, subdensely to densely white-lepidote on both sides with trichomes concentrated mainly along the nerves and not obscuring the color of the blade, apex long acuminate-caudate, acicular, pungent, margins glabrescent, subdensely spinose, spines 0.5–2 mm long, 3–8 mm apart, acicular, spreading or nearly so, pale colored at the base and yellowish-castaneous near the apex, glabrous. Peduncle erect, ca. 60 cm long, 4–6 mm in diameter, bearing subdensely to sparsely arranged glandulose trichomes, smooth, green toward the base and orange near the apex; peduncle bracts narrowly triangular-lanceolate, apex acuminate, spinescent, 20–45 × 5–7 mm, green to stramineous, nerved, inconspicuously white lepidote to glabrous, erect, densely and inconspicuously spinulose, exceeding the internodes except for the upper ones shorter than the internodes. Inflorescence erect, simple to shortly branched at base, densely covered by white glandulose trichomes except for the glabrescent or glabrous petals, the simple part 35–46 cm long, rachis straight, subangulose, orange, 3–5 mm in diameter; first order bracts resembling the peduncle bracts, distinctly exceeding the stipes; first order branches 1–4 in number, concentrated at the base of the inflorescence, forming an angle of 45° with the main axis, 4–6 cm long, with 5–10 flowers densely arranged, stipes stout, ca. 1 cm long; floral bracts narrowly triangular to triangularovate, acuminate to caudate, 8–18 × 5 mm, densely and remotely denticulate, ecarinate, bearing densely arranged white glandulose trichomes, from slightly shorter than the sepals to equaling the flowers, spreading to forming an angle of 45° with the rachis, thin in texture, soon stramineous. Flowers ca. 60 in number, ca. 15 mm long, fragrant with the fragrance produced by the glandulose trichomes even before anthesis, subspreading at anthesis to erect afterwards, subdensely to densely arranged; pedicels inconspicuous, stout, 2–3 mm long, ca. 5 mm in diameter at the apex; sepals symmetric, subovate-triangular, apex acute, 9–10 × 5 mm, orange; petals symmetric, spathulate, apex acute and slenderly apiculate, connate at the base for ca. 2 mm to form a common tube with the filaments, ca. 11 × 6 mm, ecarinate, orange, forming a somewhat tubular corolla; stamens slightly shorter than the corolla; filaments complanate, free above the common tube with the petals, 7–8 × 1.5 mm, yellowish; anthers subtriangular, strongly recurved at anthesis, ca. 2 mm long, base obtuse-bilobed apex acute, fixed near the base; pistil ca. 9.5 mm long, about equaling the anthers; stigma conduplicate-spiral, blades scalloped-lacerate, orange; style ca. 4 mm long, orange; ovary ovate, ca. 4 mm long, ca. 2.5 mm in diameter, yellowish. Capsules unknown.

Distribution and habitat:— Dyckia acutiflora is a typical dweller of the rock outcrops of the Campos Rupestres vegetation of Santo Antonio do Descoberto, Goiás state, at the locality known as Paraiso das Cascatas.

Etymology:—The name of this new species is a direct reference to its flowers with acute sepals and petals, which is a uncommon morphological combination in the genus.

Observations:— Dyckia acutiflora does not have any close morphological relationship with any known species due to its unique combination of floral morphology and the presence of abundant glandular trichomes covering most of the inflorescence. However, based on the identification key provided by Smith & Downs (1974), it is similar to the apparently variable D. remotiflora Otto & Dietrich (1833: 129) from southern Brazil and neigbouring countries, differing by the presence of abundant glandulose trichomes on the inflorescence (vs. sparsely tomentose), ecarinate sepals (vs. more or less carinate), and by the spathulate, acute and ecarinate petals (vs. trapeziform, obtuse and carinate).

On the other hand, the similar glandulose trichomes of D. acutiflora are also reported for D. glandulosa L.B. Sm. & Reitz (in Smith 1967: 484), an endemic taxon from Minas Gerais state, southeastern Brazil. However, the much narrower leaf blades of this new species (1.1–1.4 cm vs. ca. 2.3 cm wide), as well as its shorter flower pedicels (2–3 mm vs. ca. 5 mm long), acute sepals (vs. rounded), spathulate, acute and ecarinate petals (vs. suborbicular, rounded and carinate), and the distinct style (vs. none), clearly distinguish these two taxa.

Figures

FIGURE 1. A–E. Dyckia acutiflora (Leme 6806). A. Habit. B. Central portion of the inflorescence. C. Leaf rosette. D. Flowers. E. Detail of the glandulose trichomes of one sepal.

FIGURE 2. A–F. Dyckia acutiflora (Leme 6806). A. Basal portion of the leaf blade. B. Floral bract. C. Flower. D. Sepal. E. Petal and stamens. F. Pistil. G–K. Dyckia areniticola (Leme 6964 & Gonzalez). G. Leaf blade. H. Flower. I. Sepals. J. Petal and stamens. K. Pistil. Scale bars = 1 cm.