Plants perennial; usually unisexual, occasionally bisexual; strongly rhizomatous and/or stoloniferous. Culms to 60 cm, usually erect, glabrous. Leaves conspicuously distichous; lower leaves reduced to scalelike sheaths; upper leaf sheaths strongly overlapping; ligules shorter than 1 mm, membranous, serrate; upper blades stiff, glabrous, ascending to spreading, usually equaling or exceeding the pistillate panicles. Inflorescences terminal, contracted panicles or racemes, sometimes exceeding the upper leaves. Spikelets laterally compressed, with 2-20 florets; disarticulation of the pistillate spikelets above the glumes and below the florets, staminate spikelets not disarticulating. Glumes 3-7-veined; lemmas coriaceous, staminate lemmas thinner than the pistillate lemmas, 9-11-veined, unawned; paleas 2-keeled, keels narrowly to broadly winged, serrate to toothed, sometimes with excurrent veins; anthers 3. Caryopses glabrous, free from the palea at maturity, brown. x = 10. Name from the Greek distichos, two-rowed, referring to the conspicuously distichous blades.
Dioecious; spikelets flattened, 4-19-fld, the pistillate ones disarticulating above the glumes and between the lemmas; glumes unequal, obscurely veined, shorter than the lemmas; lemmas firm or coriaceous, smooth, obscurely many-veined, closely overlapping; low colonial perennial grasses from creeping scaly rhizomes with stiff, erect stems, numerous narrow, usually involute blades with overlapping sheaths, and small panicles of large, crowded spikelets. 4, New World.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.