Plants annual or perennial; synoecious; habit various, cespitose, stoloniferous, or rhizomatous. Culms 1-80 cm. Leaves usually mostly basal; sheaths open; ligules of hairs, membranous, or membranous and ciliate. Inflorescences terminal, panicles of 1-80 solitary, spikelike branches, exceeding the upper leaves; branches 4-50(75) mm, not woody, 1-sided, usually racemose on elongate rachises, sometimes digitate or subdigitate, with 1-130+ sessile to subsessile spikelets in 2 rows, axes terminating in a spikelet or extending beyond the base of the distal spikelet. Spikelets closely imbricate, appressed to pectinate, laterally compressed or terete, with 1-2(3) florets, lowest floret in each spikelet bisexual, distal florets staminate or sterile; disarticulation at the base of the branches or above the glumes. Glumes unequal or subequal, 1 or both glumes equaled or exceeded by the distal floret, 1-veined, acute or acuminate, sometimes shortly awned; lower glumes usually shorter than the lowest floret; lemmas of lowest florets entire, bilobed, trilobed, or 4-lobed, 3-veined, veins usually extended into 3 short awns; paleas of lowest florets 2-veined, veins sometimes excurrent; distal floret(s) staminate or sterile, varying from similar to the lowest floret in shape, size, and venation to sterile and reduced to an awn column with well-developed awns or to a flabellate scale. x = 10. Named for the brothers Claudio (1774-1842) and Esteban (1776-1813) Boutelou Agraz, Spanish botanists.
Spikelets with 1 perfect fl and 1 or more sterile vestiges, articulated above the glumes, inserted in 2 rows on one side of a narrow flat rachis; glumes unequal, narrow, 1-veined, acuminate to awn-pointed; fertile lemma rounded on the back, 3-veined, the lateral veins marginal or submarginal, usually excurrent below the tip into a short awn; vestige stipitate, reduced to an empty 3-awned lemma; usually tufted, the relatively short spikes 1-many, racemose on a common axis. 40, New World.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.