Muhlenbergia ciliata (Kunth) Kunth

Muhlenbergia ciliata (H.B.K.) Kunth, Rev. Gram. 1: 63. 1829
Podosaemum cilialum H.B.K. Nov, Gen, & Sp, 1: 128, 1815.
Trichochloa ciliata R. & S. Syst. Veg, 2: 386, 1817. (Based on Podosaemum cilialum H.B.K.) Polypogon cilialus Spreng. Syst. 1: 243. 1825. (Based on Podosaemum cilialum H.B.K, J Muhlenbergia adspersaTrin. Mem. Acad. St.-PHetsh.YI. 6': 291 (reprint 45). 1841. C Cynosurus
tenellus ht. Madrit. (in Kb. Mertensii!). Lima?" The specimen in Trinius' herbarium is M.
ciliata.) Podosae?num hrachyphyllum Nees; Nees & Schauer, Linnaea 19: 690. 1847. (Type from Mexico.) Polypogon brachyphyU'iis Fourn.; Hemsl. Biol. Centr. Am. Bot. 3: 552. 1885. (Based on Podosae
mum hrachyphyllum Nees.) Muhlenbergia brachyphylla Nees,* B. D. Jackson, Ind. Kew. 2: 269, 1894,
Annual; culms branching freely at the lower nodes, erect or usually la.x and .spreading, slender, glabrous, 10-30 cm. long; sheaths glabrous or sparsely pilose; ligule 0.5 mm. long; blades flat, glabrous beneath, pilose on the upper surface, spreading, lax, mostly 1—3 cm. long, sometimes longer, mostly less than 1 mm. wide, sometimes as much as 2 mm. ; panicles numerous, terminating the culms and branches, mostly 4—10 cm. long, the axis glabrous, the branches rather distant, 7-20 mm. long, spreading, closely flowered to base, the spikelets appressed on short appressed branchlets, the main branches tending finally to disarticulate from the axis just above the base; glumes narrow, glabrous, acuminate, somewhat unequal, extending into a short awn sometimes as long as the body, the second about 1 mm. long, sometimes as much as 2 mm. ; lemma very narrow, subterete, rather strongly 5-nerved, 2 mm. long or a little longer, loosely ciliate on the lateral nerves along the upper half, the short callus minutely pubescent; the awn very slender, straight or subflexuous, 5-20 mm. long; palea as long as the lemma, narrow, acuminate.
Type locality: Jorullo, Mexico.
Distribution: Moist rocks, walls, sides of ditches, and moist open ground, Mexico to Panama; also in Ecuador and Peru.

Sprawling, slender annuals. Culms 8–30 (−50) cm tall, glabrous, filiform, often tufted, freely branching at lower nodes; 0.2–0.5 mm diameter just below the inflorescence; internodes 6–42 mm long. Leaf sheaths (8−) 20–44 mm long, glabrous or sparsely pilose along the margins, shorter than the internodes; ligules 0.2–0.8 mm long, a ciliate membrane; apex truncate; margin with a tuft of hairs up to 1 mm long; blades 1–4 cm long, 0.6–1.4 mm wide, flat or loosely involute, often sparsely pilose above, glabrous below. Panicles 4–12 cm long, 1.8–5.0 cm wide, terminal, densely flowered; primary branches 1.5–3.7 cm long spreading and reflexed at maturity up to 90° from the rachises, one per node; pedicels 0.5–3 mm long, glabrous, appressed, erect; nodes 6–13 per panicle; Spikelets appressed to the branches, overlapping; glumes 0.7–1.7 mm long, subequal, glabrous, 1-nerved; apex acuminate, often mucronate; the mucro up to 0.5 mm long; lower glumes 0.7–1.5 mm long; upper glumes 0.8–1.7 mm long; lemmas 1.8–2.5 mm long, lanceolate, slender, awned, strongly 3-nerved but appearing five-nerved, the intermediate “nerves” actually rows of short barbs on top of folded epidermal ridges, sometimes with prominent short hairs (scabers) along the lateral nerves, often appearing glabrous without magnification, awns 5–11(−18) mm long, flexuous; callus minutely short pubescent; paleas 1.6–2.4 mm long, narrowly lanceolate, glabrous; anthers 0.3–0.5 mm long, yellowish. Caryopses 0.8–1.8 mm long, narrowly fusiform, brownish. 2n = 20.

Muhlenbergiaciliata is found throughout México and Central America in Ecuador, Peru, Brazil, Bolivia, Brazil and Argentina.