Herbs, usually annual [perennial] (usually unpleasantly scented). Stems sparsely or profusely branched (usually erect); glabrous, pubescent, or scabrous. Leaves: stipules (sometimes deciduous), 3-8-palmatifid, threadlike, or setaceous; petiole without pulvinus (usually longer than leaflets); leaflets (1 or) 3. Inflorescences terminal, racemes, corymbs, or flowers solitary in distal leaf axils (sometimes remaining compact in fruit); bracts usually present (pedicels often anthocyanic). Flowers actinomorphic; sepals persistent, connate basally (ca. 1/4 of length) [distinct], equal (each often subtending a nectary); petals equal; stamens 6 (usually exserted, distinct, equal); filaments inserted on a discoid or conical androgynophore, glabrous; anthers (ellipsoid), coiling as pollen is released; gynophore reflexed, spreading, or ascending in fruit. Fruits capsules, dehiscent (as long as or shorter than wide), rhomboidal, globose, deltoid, or ovoid (valves laterally expanded, falling away from round, persistent septum). Seeds 1-16, globose or reniform, not arillate, (cleft fused between ends). x = 20.

The two extraterritorial species of Cleomella are C. mexicana de Candolle and C. perennis H. H. Iltis, both known from central and northern Mexico.