Monoecious or dioecious herbs or subshrubs, with prickles or stinging hairs. Leaves 3-costate, petiolate, alternate serrate or lobed; stipules interpetiolar, leafy. In-florescence of racemosely or paniculately arranged spicate clusters of flowers. Flowers unisexual, male pedicellate; female sessile. Calyx 4-5-lobed in male, tubular; 2-3-toothed in female flowers, with broad posterior and hair-like anterior portion. Stamens 4-5: staminodes absent. Ovary upright, stigma subulate, acute, minutely papillate; pistillode globose or cup-like in male flowers. Achene much flattened, basally enclosed by persistent, enlarged calyx.