Muhlenbergia tenella (Kunth) Trin.

Muhlenbergia tenella (H.B.K.) Trin. Gram. Unifl. 192. 1824
Podosaemtnn tenellum H.B.K. Nov. Gen. & Sp, 1: 128. 1815.
,4r!iKrfo /fJiW/a Spreng. Piig. 2: 6. 1815. (Tvpe from Mexico.)
TrichocMoa lenella R. & S. Syst. Veg. 2: 385. 1817. (Based on Podosaemum tenellum H.B.K.)
Muhlenbergia Sprengelii Trin. Gram. Unifl. 189. 1824. (Based on Arundo lenella Spreng.)
Polypognn ienellus Spreng. Syst. 1: 243. 1825. (Based on Podosaemitm tenellum H.B.K.) Not
Polypogon tenellus R. Br. Polypogon gracilis Spreng. Syst. 5: 558 (Index). 1828. (Based on Polypogon tenellus Spreng) Muhlenbergia exilis Foum. Mex. PI. Gram. 84. 1886. (Type from Veracruz.)
Annual ; culms very slender, glabrous, branching from the base and lower nodes, spreading, 10-30 cm. tall; sheaths glabrous, or the lower pilose, mostly shorter than the internodes; ligule less than 0.5 mm. long, ciliate; blades flat becoming involute, glabrous beneath, pilose on the upper surface, sometimes pubescent on both surfaces, mostly less than 3 cm. long, sometimes longer, usually less than 1 mm. wide; panicles terminating the numerous culms, narrow, 5-12 cm. long, the short appressed branches floriferous to base, the spikelets appressed; glumes broad at base, the body about 0.5 mm. long, abruptly narrowed into a scabrous awn once or twice as long as the body, rarely ciliate about the base of the awn; lemma very narrow, subterete, glabrous, usually obscurely nerved, about 2 mm. long, the callus minutely pubescent, the slender awn 1-2 cm. long; palea as long as the lemma.
Type locality: Jalapa, Mexico.
Distribution: Moist banks, wet rocks and ledges, and stone walls, Mexico to Panama.