Annuals, Terrestrial, not aquatic, 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 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 2-10 mm wide, Leaf blade margins f olded, involute, or conduplicate, Leaf blades mostly glabrous, Leaf blades more or less hairy, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence a contracted panicle, narrowly paniculate, branches appressed or ascending, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence single raceme, fascicle or spike, Flowers bisexual, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 3-7 florets, 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 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 shorter than adjacent le mma, Glumes awn-like, elongated or subulate, Glumes 1 nerved, Glumes 3 nerved, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma 3 nerved, Lemma 5-7 nerved, Lemma glabrous, Lemma body or surface hairy, Lemma apex acute or acuminate, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn less than 1 cm long, Lemma awned from tip, Lemma awns straight or curved to base, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea about equal to lemma, Palea 2 nerved or 2 keeled, Stamens 1, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.
Slender, decumbent to erect annual 1-6 dm, glabrous or hairy; blades flat or involute, setaceous, 0.5-1 mm wide; infl slender, 3-20 cm, with a few ascending or rarely spreading branches; spikelets flattened, with 5-11+ fls; first glume subulate, 1- veined, 1.7-4.5 mm, the second lanceolate, 3-veined, a fourth longer; florets closely imbricate, the internodes of the rachilla typically 0.5-0.7 mm; lemmas involute, straight, obscurely veined, glabrous or merely scabrous in our vars., soon diverging and exposing the rachilla, the lowest one 2.7-6.5 mm, with an awn 0.3-6(-9) mm; anther 1(-3), 0.3-1.5 mm; grains mostly 1.7-3.3 mm; 2n=14. Dry or sterile soil; Que. and N. Engl. to B.C., s. to Fla. and Calif. (Festuca o.) Two ill-defined vars. in our range: In the mostly southern var. octoflora the spikelets are 5.5-10 mm, and the awn of the lowest lemma is 0.3-3 mm. In the mostly more northern var. glauca (Nutt.) Fernald the spikelets are 4-5.5 mm, and the awn of the lowest lemma is 2.5-6+ mm.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.