Mexican Gamagrass

Tripsacum acutiflorum Fourn. Bull. Soc. Bot. Belg. 15 : 466. 1876
Tripsacum lanceolatum Rupr.; Fourn. Mex. PI. Gram. 68. 1881.
Stems up to 1 m. tall, glabrous ; leaf -sheaths glabrous or sometimes ciliate on the margin ; blades up to 5 dm. long, 1-2 cm. wide, long-acuminate, narrowed toward the base, pubescent on the upper surface ; spikes up to 2 dm. long, slender, the pistillate portion occupying about one half the length and 3-4 mm. in diameter ; pistillate spikelets 4-5 mm. long, the outer scale ovate, acute ; staminate spikelets 6-7 mm. long, one sessile, the other with a pedicel about 1 mm. long, the outer scales oblong-lanceolate, obtuse, glabrous.
Type locality : Mexico.
Distribution : L,ower California and Sonora to Durango and Oaxaca.

Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome short and compact, stems close, Stems nodes swollen or brittle, Stems erect or ascending, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes solid or spongy, Stems with inflorescence 1-2 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 1-2 cm wide, Leaf blades 2 or more cm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Leaf blades more or less hairy, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Inflorescence terminal, Inflorescence solit ary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence with 2-10 branches, Flowers unisexual, Plants monoecious, Spikelets pedicellate, Spikelets sessile or subsessile, Spikelets dorsally compressed or terete, Spikelet 3-10 mm wide, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 2 florets, Spikelets solitary at rachis nodes, Spikelets unisexual, Spikelets disarticulating below the glumes, Spikelets disarticulating beneath or between the florets, Spikelets falling with parts of disarticulating rachis or pedicel, Inflorescence branches deciduous, falling intact, Spikelets closely appressed or embedded in concave portions of axis, Monoecious - staminate and pistillate spikelets on same inflorescence, Glumes present, empty bracts, Glumes 2 clearly present, Glumes distinctly unequal, Glumes equal to or longer than adjacent lemma, Lemmas thin, charta ceous, hyaline, cartilaginous, or membranous, Lemma glabrous, Lemma apex truncate, rounded, or obtuse, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Palea membranous, hyaline, Palea shorter than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.