Muhlenbergia cenchroides (Humb. & Bonpl. ex Willd.) P. M. Peterson

Aegopogon breviglumis (Scribn.) Nash, sp. nov
Aegopogon geminiflorus breviglumis Scribn. Zee 4 : 386. 1894.
Stems 1-5 dm. tall, very slender; leaf-sheaths smooth and glabrous; blades usually 1-5 cm. long, rarely 1 dm., up to 1.5 mm. wide, glabrous, or sometimes puberulent on the upper surface; inflorescence 2-8 cm. long, sometimes interrupted below; spikelet-clusters 2.5-3 mm. long, exclusive of the awns and peduncle, of 2 or 3 spikelets, one spikelet sessile or short-pedicellate, perfect, the other 1 or 2 with longer pedicels, staminate or empty, sometimes rudimentary; empty scales short, 1 -nerved, the nerve running out into an awn 3 times as long as the scale or more, 2-toothed or 2-lobed at the apex, the teeth or lobes acute, the scales sometimes reduced to an awn only; flowering scale of the perfect spikelet 3-lobed at the apex, 3-nerved and 3-awned, the midnerve running out into a long awn usually 3-4 times as long as the scale, the lateral nerves very acute, awned, the awn several times as long as the lobe with usually an acute tooth at the base, the flowering scale of the other spikelets similar or sometimes reduced to awns.
Type locality : Saucito, I,ower California. Distribution ; I,ower Caliifornia, Jalisco, and Colima.

Aegopogon cenchroides H. & B.; Wilid. Sp. PL 4 : 899. 1806
Aegopogon geminiflorus H.B.K. Nov. Gen. & Sp. 1 : 133. 1815.
Hymenothecium triseium I^ag. Gen. Sp. PI. 4. 1816.
Hymenothecium quinquesetum I^ag. Gen. Sp. PI. 4. .1816.
Aegopogon irisetus R. & S. Syst. Veg. 2 : 805. 1817.
Aegopogon quinqueseius R. & S. Syst. Veg, 2 : 805. 1817.
? Aegopogon seiiferl<l^^s^ I^innaea 19 : 691. 1847.

Caespitose perennials often sprawling, occasionally with stolons. Culms (10–) 25–55 cm long, glabrous below the nodes; internodes glabrous. Leaf sheaths mostly 0.8–8 cm long, shorter than the internodes, glabrous; ligules 1–2 mm long, apex acute, lacerate; blades 1.5–6 cm long, 0.5–2 mm wide, flat, scaberulous above, smooth beneath. Panicles 2–8 cm long, 0.5–1.2 cm wide, open, loosely-flowered with recemosely arranged branches; primary branches 2–4 mm long, excluding the awns, one per node, often purplish. Spikelet fasciles of three with one sessile or subsessile perfect spikelet and two short-pedicelled lateral spikelets staminate or sterile, the pedicels less than 0.2–0.5 mm long and the other two spikelets short-pedicelled, the pedicels about 0.7–1.2 mm long; glumes (1−)1.5–2.8 mm long, oblong and wider distally, 1-veined, apex deeply notched, awned, the awns 2–4 mm long, lobes triangular, acute; lemmas 2.5–3 mm long, fusiform, 3-awned, the central awns 5–13 mm long, lateral awns 2–3 mm long; paleas 2.5–3 mm long, puberulent, apex awned, the awns 1–2 mm long; anthers 1.6–1.8 mm long, yellowish to purplish. Caryopses 1−1.4 mm long, fusiform. 2n = 40, 60, 80.

Muhlenbergiacenchroides ranges from throughout México, Central America to South America in Bolivia, Brazil, Colombia, Ecuador, Peru, Guyana and Venezuela.

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems ca espitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence branches more than 10 to numerous, Inflorescence branches 1-sided, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Sp ikelet with 1 fertile floret and 1-2 sterile florets, Spikelets 3 per node, Spikelets with 1 terminal fertile floret and 2 lateral staminate or sterile florets, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets falling with parts of disarticulating rachis or pedicel, Spikelets secund, in rows on one side of rachis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes shorter than adjacent lemma, Glumes awned, awn 1-5 mm or longer, Glumes 1 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 3 nerved, Lemma glabrous, Lemma apex dentate, 3-5 fid, Lemma distinctly awned, more than 2-3 mm, Lemma with 3 awns, Lemma awn less than 1 cm long, Lemma awned from tip, Lemma awns straight or curved to base, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea about equal to lemma , Palea 2 nerved or 2 keeled, Palea keels winged, scabrous, or ciliate, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Aegopogon cenchroides es una especie de planta herbácea de la familia de las poáceas, es originaria del sudoeste de Estados Unidos, hasta Venezuela.