Monoecious, perennial herbs, with non-stinging hairs and dot-like cystoliths. Leaves 3-costate, alternate, crenate-dentate; stipules free. Inflorescence of axillary, sessile, cymose bisexual clusters enclosed by tubular-campanulate, densely hairy involucre of 3-6, slightly connate bracts. Flowers minute, unisexual; female surrounded by a ring of male flowers. Calyx tubular, 3(5)-lobed in male, absent in female flowers. Stamen solitary. Ovary upright, wooly, style absent, stigma filiform, papillate-hispid, shortly persistent; pistillode absent in male flowers. Achenes ovate or ovoid-elliptic, flattened, densely hairy, enveloped in woolly involucre.