Tetrapogon chlorideus (J. Presl) P. M. Peterson

Chloris chloridea (Presl) Hitchc. Proc. Biol. Soc. Wash 41:162. 1928.
Dineba chloridea Presl. Rel. Haenk. I: 291. 1830. (Type from Mexico. Haenke.)
Eulriana chloridea Kunth. R^v, Gram. Suppl. XXIII. 1830. (Based on Dineba chloridea Presl.)
Gymnopogon longifolius Foum. Mex. PI. Gram. 2; 144. 1886. (Type from Vera Cruz, Mexico,
Gouin 52.) Gymnopogon Virlelii Foum. Mex. PI. Gram. 2: 144. 1886. (Type from San Luis PotosI, Mexico,
Virlet 1441.) Chloris longifolia Vasev, Contr. U. S. Nat. Herb. 1: 284. 1893. (Based on Gymnopogon longifolius
Foum.) Not C. longifolia Steud., 1854. Chloris clandesiina Scribn. & Merr. Bull. U. S. Dep. Agr. Agrost. 24: 25. 1901. (Based on Gymnopogon longifolius Fourn.)
Perennial; culms tufted, erect, 50-110 cm. tall, bearing cleistogamous spikelets on the slender branches of underground stems; sheaths longer than the internodes, glabrous, keeled, the keel sometimes obscure; ligule very short, ciliate; blades flat, attenuate-pointed, narrowed toward the base, as much as 30 cm. long, 5-9 mm. wide, glabrous on both surfaces, the margins scabrous; spikes 5-13 (usually less than 10), 8-18 cm. (usually about 12 cm.) long, stiffly ascending or spreading, approximate or relatively distant on the axis; spikelets 6-7 mm. long, appressed; glumes acute, 1-nerved, the first 1-1.5 mm. long, the second broader, 2-3.5 mm. long; fertile floret 6-7 mm. long, the lemma acuminate, the callus bearded, more or less hispid on the margins in the upper half, otherwise glabrous, the awn 7-15 mm. long, very scabrous; rudiment very narrow, about 2 mm. long, the awn 4-8 mm. long, scabrous; cleistogamous spikelets solitary, 6-7 mm. long, terminating the slender branchlets.
Typb locality: Mexico {Haenke).
Distribution: Open ground and waste places, Texas (Brownsville) and Mexico.

Perennials, Terre strial, not aquatic, Rhizomes present, Rhizome elongate, creeping, stems distant, Stems nodes swollen or brittle, Stems erect or ascending, Stems caespitose, 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 basal, below middle of stem, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath hairy, hispid or prickly, Leaf sheath hairy at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades more or less hairy, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Inflorescence terminal, Inflorescence a dense slender spike-like panicle or raceme, branches contracted, Inflorescence solitary, with 1 spike, fascicl e, glomerule, head, or cluster per stem or culm, Inflorescence a panicle with digitately arranged spicate branches, Inflorescence with 2-10 branches, Inflorescence branches more than 10 to numerous, Inflorescence branches paired or digitate at a single node, Rachis angular, Flowers bisexual, Spikelets sessile or subsessile, Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Spikelets disarticulating beneath or between the florets, Spikelets subterranean, cleistogamous, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes distinctly unequal, Glumes shorter than adjacent lemma, Glumes 1 nerved, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma 3 nerved, Lemma glabrous, Lemma apex dentate, 2-fid, Lemma distinctly awn ed, more than 2-3 mm, Lemma with 1 awn, Lemma awn less than 1 cm long, Lemma awn 1-2 cm long, Lemma awn from sinus of bifid apex, Lemma awns straight or curved to base, Lemma margins thin, lying flat, Lemma straight, Callus or base of lemma evidently hairy, Callus hairs shorter than lemma, Palea present, well developed, Palea membranous, hyaline, Palea about equal to lemma, Palea 2 nerved or 2 keeled, Stamens 1, Stamens 2, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.