Annual or perennial herbs or woody subshrubs, hispid (sometimes puberulent), hairs often urticating. Leaves petiolate, blades suborbicular to broadly ovate, angular, palmately lobed to digitately divided, truncate, serrate, acute to obtuse, usually pubescent; stipules filiform, relatively persistent. Flowers in condensed bracteate, head-like, axillary or terminal racemes. Subtended by specialized floral bracts.Floral bracts deeply cordate and foliaceous, often white intercostally at base. Epicalyx absent (except present in M. radiata where it is 10 lobed and hispid).). Calyx small, deeply 5-lobed. Costae sometimes present (M. fasiata has whitish intercostal areas).Corolla white, yellow, or lavender, often inconspicuous. Staminal column included, anthers are scattered along column with 5 apical teeth. Styles 10, stigmas capitate. Fruits schizocarpic, glabrous or puberulent. Mericarps 5, usually smooth or reticulately costate, 1-seeded, seeds glabrous. Endoglossum unknown.