Annual or perennial plants, mostly herbaceous, some woody (bamboos), with mostly erect stems, or these sometimes creeping horizontally, either above or below ground (stolons or rhizomes); leaves mostly long and narrow, flat, folded, or sometimes rolled, always simple, of two parts, a tubular sheath and an expanded blade, attached at a node (often thickened and solid), with a ligule at the junction of blade and sheath, and veins parallel; leaves alternate; rarely 2-ranked; branches produced from or through the sheath. Inflorescences compact and small to large and spreading, composed of spikelets, each bearing one or more florets, these distichous, sessile or shortly stalked (pedicellate), with a glume at the base; flowers small, bisexual or unisexual, with 1 to 5 but usually 3 stamens, borne within 2 (rarely 1 or 3) fleshy scalelike lodicules; pistil 1, of one single-celled ovary, with 2 (rarely 1 or 3) styles; fruit a caryopsis, with starchy endosperm, the embryo small and at the base.