Annual or perennial, glabrous herbs. Stolons often present in perennials. Culms ranging from 1-2 cm to 150 cm, green, terete, angular or triangular, hollow or filled with pith, smooth or ridged, rarely with transverse septa (E. dulcis). Sheaths pale, tubular, truncate above or ending in a short lobe. Leaves 0. Inflorescence a single terminal spikelet. Lowest 1-2 glumes similar to or different from upper. Glumes spirally arranged, usually numerous; margin often transparent. Perianth segments 3-9 glabrous or barbellate bristles or 0. Stamens 1-3. Nutlet with the style base persistent as an appendage (the style base excluded in all nutlet measurements).