Systematic Botany (2011), 36(1): pp. 53–58 © Copyright 2011 by the American Society of Plant Taxonomists DOI 10.1600/036364411X553126 New Species of Paniceae (Poaceae, Panicoideae) from Brazil Diego L. Salariato , 1 , 2 Osvaldo Morrone , 1 and Fernando O. Zuloaga 1 1 Instituto de Botánica Darwinion, Labardén 200, Casilla de Correo 22, B1642HYD, San Isidro, Buenos Aires, Argentina 2 Author for correspondence (
[email protected] ) Communicating Editor: Molly Nepokroeff Abstract— Two new species of Paniceae are here described, one belonging to Dichanthelium ( Dichanthelium barbadense ) and the other to Panicum sect. Laxa ( Panicum harleyi ). Both taxa grow in open areas of Central Brazil are described, illustrated, and compared with putative related species. Keywords— Dichanthelium , Gramineae , grasses , Panicum , taxonomy. During a revision of the Paniceae for the Neotropics, two to sparsely pilose, subcordate at the base, the apex acute, mar- new species were discovered from Brazil and are described gins long-ciliate, scabrous, involute toward the apex. Peduncle below. One belongs to Dichanthelium (Lam.) Gould and the up to 3 cm long, included in the uppermost leaves or partially other is placed in Panicum sect. Laxa (Hitchc. & Chase) Pilg. exerted, shortly pilose to glabrous. Inflorescence 3–5 × 1–2 cm, Dichanthelium an American genus with nearly 55 species dis- lax, few flowered panicle; main axis wavy, sparsely pilose tributed from Canada and the U. S. A. to Argentina ( Zuloaga near the branches, otherwise smooth, glabrous; pulvini pilose, et al. 1993 ; Aliscioni et al. 2003 ) is characterized as including with long whitish hairs; first order branches up to 0.8 cm long, perennial species with or without foliar dimorphism, mem- divergent or appressed, alternate, axis of the branches smooth, branous-ciliate ligules, spikelets ellipsoid to obovoid with glabrous, delicate, terete; pedicels 2–5 mm long, claviform, the upper glume and lower lemma (5–)7–15 nerved, and the with long whitish hairs toward the base.