Perennial herbs or undershrubs. Stem ± erect, densely covered by cottony or woolly growth. Leaves sessile or petiolate, alternate, rarely subopposite to opposite. Capitula discoid and dioecious or disciform, arranged in flat-topped terminal corymb, rarely solitary, dimorphic and of two types borne on separate plants. Florets unisexual or functionally unisexual, either predominantly female, with a few central male florets or male or bisexual but functionally male with few outer female florets. Involucre campanulate, turbinate or subglobose, usually woolly at base; phyllaries 2 to many-seriate, scarious, white or pinkish, opaque. Receptacle convex, naked. Disc florets, yellow. Cypselas diamorphic, with short clavate not myxogenic twin hairs, in predominantly female capitula, cypselas of the male florets vestigial and usually absent in predominantly male capitula; pappus simple, just exceeding the corollas, bristles barbellate, basally with patent cilia.