Description: Shrubs or trees, dioecious.
Leaves alternate, entire to toothed.
Heads unisexual with male and female on separate plants, terminal or axillary, in panicles, corymbs or racemes, sessile or pedunculate; involucral bracts scarious to ± herbaceous, ± equal to strongly imbricate in several series; receptacle naked. Ray florets absent. Disc florets ± numerous, white to yellowish or greenish; female florets fertile, tubular-filiform, 5-toothed; bisexual florets functionally male, tubular, 5-toothed. Anthers obtuse at the base. Style branches subulate, sometimes fused, hairy.
Achenes ± compressed, ribbed; pappus of numerous hair-like bristles, those of the male flowers fewer, shorter and ± plumose tipped.
Distribution and occurrence: World: c. 400 species, America. Australia: 1 species (naturalized).
Text by M. F. Porteners