Sprucetop Grama

Bouteloua chondrosioides (H.B.K.) Benth.; S. Wats. Proc Am. Acad. 18: 179. 1883.
Dinebra chondrosioides H.B.K. Nov. Gen. & Sp. 1: 173. 1816.
BoM(e/oMa ODo/a Lag. Gen. & Sp. Nov. 5. 1816. (Type from Mexico.)
Atheropogon chondrosioides R. & S. Syst. Veg. 2: 416. 1817. (Based on Dinebra chondrosioides
H.B.K.) Actinochloa ovala R. & S. Syst. Veg. 2: 420. 1817. (Based on Bouteloua ovata Lag.) Eutriana cristata Trin. Gram. Unifl. 241. 1824. (Based on Atheropogon chondrosioides R. & S.) Chondrosium Humboldlianum Kunth, R^v. Gram. 93. 1829. (Based on Dinebra chondrosioides
H.B.K.) ?£:rttcaria t>i7fe)5o Cerv. Naturaleza 1: 348. 1870. (Mexico.)
Bouteloua Havardii Vasey; S. Wats. Proc. Am. Acad. 18; 179. 1883. (Type from Limpio Mountains, Texas, Havard in 1881.)
Perennial; culms tufted, erect, 15-55 cm. tall, glabrous; leaves clustered toward the base, the sheaths glabrous, hispid at the throat, the blades flat, firm, 4-12 cm. (rarely more than 15 cm.) long, 2-3 mm. wide, glabrous or sparsely hispid, the margins often papillose-ciliate toward the base; Ugule ciliate, about 0.5 mm. long; spikes 3-8, falling entire, ascending or spreading, rhomboid, tinged with purple, 1-1.5 cm. (rarely to 2 cm.) long, the rachis densely long-ciliate on the margin; spikelets crowded, appressed or more or less pectinately arranged; first glume 3-5 mm. long, acuminate, ciliate on the keel; second glume 7-8 mm. long, acuminate, hairy; lemma about 7 mm. long, hairy, especially on the midnerve and margins, the tip threetoothed, awnless; awns of the rudimentary floret 5-10 mm. long, scabrous.
Type locality: Michoacan {Humboldt &• Bonpland).
Distribution: Mesas and rocky hills, Texas and southern Arizona to Costa Rica.

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 hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, 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 mostly flat, Leaf blades more or less hairy, Leaf blades glaucous, blue-green, or grey, or with white glands, Ligule present, Ligule a fringe of hairs, 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, 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, Inflorescence branches deciduous, falling intact, 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 equal to or longer than adjacent lemma, Glume equal to or longer than spikelet, Glume surface hairy, villous or pilose, Glumes 1 nerved, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma 3 nerved, Lemma glabrous, Lemma body or surfac e hairy, Lemma apex dentate, 3-5 fid, Lemma awnless, 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 chondrosioides, commonly known as sprucetop grama, is a perennial bunchgrass native to southern Arizona and northern Mexico.