Dichanthelium barbadense Salariato, Morrone & Zuloaga, 2011

Dichanthelium barbadense Salariato, Morrone & Zuloaga View in CoL ,

sp. nov.— TYPE: BRAZIL. Bahia: Abaíra, Pico do Barbado,

13°17 ¢ 0.04 ²² S, 41°55 ¢ 59.94 ² W 1,800 –2,430 m, 15 Aug 1998,

A. M. Giulietti, G. L. Campos, A. S. Conceição, A. T. Brito &

R. P. Oliveira 1454 (holotype: HUEFS!).

Dichanthelium congesto affine sed spiculis non stipitatis, gluma inferiore ½ spiculam aequans vel breviore, gluma superiore 9–11-nervia, differt.

Short rhizomatous perennials, caespitose. Culms 15–40 cm tall, many noded, erect, freely branching, more so toward the middle and upper nodes; internodes 0.5–3 cm long, hollow, terete, shortly pilose, barbate; nodes compressed, dark, pilose. Sheaths 1.2–3 cm long, usually longer than the internodes, overlapping, striate, the margins long ciliate toward the apex, otherwise sparsely pilose to glabrous. Ligules 0.2–0.4 mm long, membranous- ciliate, the membranous portion reduced, with long hairs beneath at the base of the blade; collar pale, pilose. Blades 1–3 × 0.4–0.5 cm, ovate-lanceolate to lanceolate, flat, hispid on both surfaces with papillose-pilose hairs to sparsely pilose, subcordate at the base, the apex acute, margins long-ciliate, scabrous, involute toward the apex. Peduncle up to 3 cm long, included in the uppermost leaves or partially exerted, shortly pilose to glabrous. Inflorescence 3–5 × 1–2 cm, lax, few flowered panicle; main axis wavy, sparsely pilose near the branches, otherwise smooth, glabrous; pulvini pilose, with long whitish hairs; first order branches up to 0.8 cm long, divergent or appressed, alternate, axis of the branches smooth, glabrous, delicate, terete; pedicels 2–5 mm long, claviform, with long whitish hairs toward the base. Spikelets 3–3.2 × 1.2– 1.4 mm, long-ellipsoid, acute, green or tinged with purple, glabrous, upper glume and lower lemma acuminate, exceeding the upper anthecium in length. Lower glume 1.2–1.6 mm long, ca. ½ or less the length of the spikelet, ovate, subulate, hyaline, glabrous, 1–3-nerved, the nerves not manifest, not embracing the upper glume. Upper glume as long as the spikelet, glabrous to sparsely pilose, 9–11-nerved, tinged with purple at the apex. Lower lemma as long as the spikelet, glumiform, glabrous to sparsely pilose, 9-nerved. Lower palea 2.4–2.6 × 1.2 mm, ovate, hyaline, the margins ciliolate, apex acute; lower flower absent. Upper anthecium 2.4 × 1.2 mm, ellipsoid, apiculate, pale, with simple papillae regularly distributed all over its surface, shortly pilose at the apex ( Fig. 2 View FIG ); lodicules ca. 0.4 mm long, 2, truncate; stamens 3. Caryopsis not seen. Figure 1 View FIG .

Etymology— The name refers to the locality “Pico do Barbado”, type locality of the species. Pico do Barbado is the highest mountain in the Brazilian state of Bahia.

Distribution and Habitat— Only known from “campos rupestres,” rock fields, of Chapada Diamantina in Bahia, where this rare species grows in open, shrubby savannas, between 1,100 and 2,400 m elevation, together with species of Apochloa Zuloaga & Morrone and Renvoizea Zuloaga & Morrone ( Poaceae ), and genera of Velloziaceae and Eriocaulaceae .

Observations— Dichantheliumbarbadense isrelated, byitsdistribution and morphology, to D. congestum (Renvoize) Zuloaga and D. stipiflorum (Renvoize) Zuloaga ; all these species grow within the Espinhaço range, Chapada Diamantina, in northeastern Brazil, although they do not overlap in its present distribution. Dichanthelium congestum differs by having a lower glume ¾ or more the length of the spikelet, 5–7-nerved, with a conspicuous internode between both glumes. Dichanthelium stipiflorum is distinguished by its cordate, clasping blades, and spikelets densely hirsute with a conspicuous stipe between the lower and upper glume. Dichanthelium barbadense shares, with other species of Dichanthelium , a non Kranz anatomy, with more than four mesophyll cells between consecutive vascular bundles, and also extensions of the outer bundle sheath adaxially and abaxially ( Fig. 3 View FIG3 , A-B).