Sixweeks Grama

Bouteloua barbata Lag. Var. Ci. 4: 141. 1805
Aclinochloa barbata R. & S. Syst. Veg. 2: 420. 1817. (Based on Bouteloua barbata Lag.)
Eutriana barbata Kunth, R^v. Gram. 96. 1829. (Based on Boutdotia barbata Lag.)
Chondrosium polystachyum Benth. Bot. Voy. Sulph. 56. 1844. (Type from Magdalena Bay, Baja
California, Barclay.) Chondrosium subscorpinides C Miill.Bot.Zeit. 14:347. 1856. (Type from Baja California, Barclay.) Bouteloua polystachya Torr. Pacif. R. R. Rep. 5: 366. 1856. (Based on Chondrosium polystachyum
Benth.) Bouteloua pumila Buckl. Proc. Acad. Phila. 1862: 93. 1862. (Type from Texas, Wright 754.) Erucaria tetrastachya Cerv. Naturaleza 1: 349. 1870. (Type from Mexico.) Bouteloua polystachya var. (?) major Vasey, in Rothr. Bot. Wheeler's Surv. 287. 1878. (Type
locality, Sanoita Valley. Arizona, Rolhrock 691.) Chondrosium exile Fotirn. Mex. PI. Gram. 2: 137. 1886. (Type from Mexico, Berlandier 842.) Chondrosiion microsiachyum Foum. Mex. PI. Gram. 2: 138. 1886. (Type from Guadalupe, Mexico,
Bourgeau 667.) Bouteloua arenosa Vasey, in S. Wats. Proc. Am. Acad. 24: 81, name only. 1889; Bull. U. S. Dep.
Agr. Bot. 12': no. 34. 1890. (Type from Guaymas, Mexico, Palmer 189.) Bouteloua microstachya L. Dewey, Contr. U. S. Nat. Herb. 2: 531. 1894. (Based on Chondrosium
microsiachyum Foum.) Bouteloua micrantha Scribn. & Merr. Circ. U. S. Dep. Agr. Agrost. 32: 8. 1901. (Type from Fort
Lowell, Arizona, Griffiths 1556.)
Annual; culms slender, branching, geniculate, decumbent-spreading, mostly 10-30 cm. tall; sheaths glabrous, shorter than the internodes; ligule ciliate, nearly I mm. long; blades flat, acuminate, 1-6 cm. long, 1-2 mm. wide, scabrous above, glabrous below; spikes 4-6 (sometimes only 3), 1-3 cm. long, ascending to spreading; first glume hyaline, acuminate, 1.5-2 mm. long, the second acute or acuminate, sometimes subobtuse and mucronate, 2-3 mm. long, scabrous; lemma 2-4 mm. long, densely villous at least on the margins, and often over the entire back, the awns from shorter than the lobes to 3 mm. long; rudiment more or less bearded at the base, deeply cleft, the lobes obtuse, the awns about as long as those of the lemma.
Typb locality: Mexico.
Distribution: Open ground, rocky hills, and waste places, Texas to southern LTtah and southern California; Mexico.

Bouteloua sonorae D. Griff. Contr. U. S. Nat. Herb 14:389. 1912.
Stoloniferous perennial; culms tufted, branching, geniculate-spreading, or usually solitary, erect from the distant nodes of the stolons, glabrous; ligule ciliate, 1-1.5 mm. long; blades flat or loosely involute, 2-6 cm. long, 1-2 mm. wide, scabrous on the upper surface, glabrous on the lower; spikes 4-6, 1-2 cm. long, ascending or spreading, curved; glumes acute, glabrous, or scabrous on the keel, the first 1 mm. long, the second 2 mm. long; lemma 2.5 mm. long, deeply cleft for one third of its length, the lobes obtuse or subacute, minutely erose, the awns from between the lobes about 1.5 mm. long, scabrous; rudiment cleft to the base, the intermediate lobes 1 mm. long, obtuse, the awns 2-3 mm. long, the rachilla with a tuft of spreading hairs at the summit.
Type locality: "Yaqui River," Sonera (Palmer).
Distribution: Gravelly or stony ground near the sea, northwestern Mexico.

Bouteloua rothrockii Vasey, Contr. U. S. Nat. Herb 1:268. 1893.
Perennial, or sometimes flowering the first year and appearing like an annual; culms tufted, erect or rarely decumbent at the base, branching, mostly 20-60 cm. tall (rarely less), glabrous; sheaths shorter than the intemodes, glabrous; ligule ciliate, I mm. long; blades flat, acuminate, 5-15 cm. long, 1-3 mm. wide, scabrous, the margins papillose-eiliatc toward the base; spikes 4-8, appressed to spreading, 1.5-4 cm. long, the rachis scabrous; first glume obtuse, hyaline, 1.5 mm. long; second glume broader, 3 mm. long, pubescent, shortawned from between the short irregular teeth; lemma 3 mm. long, densely villous with spreading hairs on the lower part of the back and margins, the awns 2-3 mm. long; rudiment 1.5 mm. long, bearded at the base, the lobes cucullate, the awns about 3 mm. long.
Type locality: Cottonwood, Arizona [Rothrock 347).
Distribution: Mesas, sandy plains, and rocky hills, Arizona, southern California, and northern Mexico.

Annuals, Terrestrial, not aquatic, Stolons or runners present, Stems trailing, spreading or prostrate, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, 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 smooth, glabrous, Leaf sheath hairy at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Inflorescence terminal, Inflorescence with 2 or more spikes, fascicles, glomerules, heads, or clusters per culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence with 2-10 branches, Inflorescence branches 1-sided, Inflorescence branches terminating in bristle or point, Flowers bisexual, Spikelets sessile or subsessile, Spikelets laterally compressed, 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 secund, in rows on one side of rachis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes distinctly unequal, Glumes equal to or longer than adjacent l emma, Glume equal to or longer than spikelet, Glumes 1 nerved, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma 3 nerved, Lemma glabrous, Lemma body or surface hairy, Lemma apex dentate, 3-5 fid, Lemma teeth unequal. central tooth longer, Lemma distinctly awned, more than 2-3 mm, Lemma with 3 awns, Lemma awn less than 1 cm long, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea shorter than lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Bouteloua barbata is a species of grass known by the common name six-weeks grama native to North America.