Pereilema beyrichianum (Kunth) Hitchc.

Pereilema beyrichianum (Kunth) Hitchc. Contr. U. S Nat. Herb. 24: 385. 1927.
M uhlenbergia Beyrichiana Kunth, Rev. Gram. 63, nomen nudum. 1829; Enum. PI. 1: 200. 1833. Pereilema brasilianum Trin. Mem. Acad. St.-Petersb. VI. 6 2 : 382. 1841. (Type from Brazil.)
Culms often rather stout, erect or usually branching and spreading at base and often rooting at the lower nodes, often several-noded, as much as 1 meter tall; sheaths scaberulous; ligule rather firm, 0.5 mm. long; blades flat, thin, scabrous, 5-15 cm. long, mostly 2-5 mm. wide, auricled at base, the auricles strongly ciliate; panicles 5-15 cm. long, the branches not deciduous, spreading or sometimes reflexed, all except the upper distant, the lower as much as 4 cm. long, the axis angled, scabrous; bristles about as long as the awns of the glumes or shorter; glumes thin, hyaline, glabrous, about 1 mm. long, the awns 3-4 mm. long; lemma rather strongly nerved, scabrous, short-pilose at base, 2-3 mm. long, the awn 1.5-2 cm. long; palea about as long as the lemma.
Type locality: Brazil.
Distribution: Open ground, stone walls, and shady banks, Costa Rica to Brazil and Ecuador.

Caespitose annuals. Culms 30−80 cm tall, slender, terete, glabrous, often branching from the aereal nodes below, usually with stilt-roots from lower nodes. Leaf sheaths usually shorter than the internodes, furrowed, scabrous; ligules 0.5−0.7 mm long, membranous; auricles 1−2 mm long, ciliate, sometimes cauducous at maturity, the cilia about 1 mm long; blades 8−20 cm long, 3−6 (−8) mm wide, flat, scabrous, apex attenuate. Panicles 5−16 (−20) cm long, 1−2.5 cm wide, contracted, spike-like, interrupted, the branches widely spaced along the rachis; primary branches 1−3 cm long, appressed, ascending or divergent and spreading. Spikelets in dense clusters of 2−4 subtended by 10−15 bristles, the bristles 1−5 mm long; glumes 0.7−1 mm long, ovate, membranous, 1-veined, apex awned, bidentate, the awns 3.5−5 mm long; lemmas (1.2−) 2−2.2 mm long, lanceolate, 3-veined, cartilaginous, scaberulous, awned, the awns 10−16 (−20) mm long, straight; callus short, the hairs 0.2−0.4 mm long; paleas as long as the lemmas, 2-veined, these often extending into mucros 0.1−0.3 mm long; stamens 3, anthers 0.7−1 mm long, purplish. Caryopses 1−1.3 mm long, ellipsoid.

Muhlenbergiabeyrichiana is known to occur in Brazil, Ecuador and Peru. Earlier, it was reported in Mexico and Central America but these are probably an error for Muhlenbergiadiandra (R.W. Pohl) Columbus, a more recently described species that superficially resembles M.beyrichiana (Espejo Serna et al. 2000; Lægaard and Peterson 2001; Peterson et al. 2001).

Pereilema beyrichianum là một loài thực vật có hoa trong họ Hòa thảo. Loài này được (Kunth) Hitchc. mô tả khoa học đầu tiên năm 1927.