Tripsacum laxum Nash

Tripsacum laxum Nash
Tripsacum fasciculatum Trin.; Aschers. Bot. Zeit. 35 : 525. 1877. Not T. fasciculatum Rasp. 1825.
Stems 1-2 "m. tall, glabrous ; leaf-sheaths glabrous ; blades up to 8 dm. long and 7 cm. wide, glabrous, long-acuminate ; spikes usually numerous, sometimes few, flexuous, slender, up to 2 dm. long ; pistillate spikelets about 5 mm. long, the outer scale ovate ; staminate spikelets 4-6 mm. long, one sessile or rarely on a short pedicel, the other on a slender pedicel 3-4 mm. long.
Type locality : Hacienda de la Laguna, Mexico. Distribution : Southern Mexico.

Perennials, Terrestrial, not aquatic, 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 with inflorescence 2-6 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 2 or more cm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Inflorescence terminal, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence lax, widely spreading, branches drooping, pendulous, Inflorescence curved, twisted or nodding, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence a panicle with digitately arranged spicate branches, Inflorescence branches more than 10 to numerous, Inflorescence branches paired or digitate at a single node, 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, Spik elets 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, Rachilla or pedicel glabrous, 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, chartaceous, 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.

Tripsacum laxum, the Guatemalan gamagrass, is a species of grass in the family Poaceae. It is a larger perennial bunchgrass of the Caribbean, Central America, such as in Nicaragua and Guatemala, and North America in southern Mexico.