Annual or biennial, taprooted herbs, usually hispid to some degree. Leaves 2–3-pinnate. Inflorescence a terminal compound umbel; central flowers often sterile and reduced to purple or black bristles; bracts several, or lacking. Fertile flowers bisexual; sepals small or absent; petals obovate, 2-lobed with an inflexed apex; nectary conical. Fruit oblong-ovoid, cylindrical or dorsally slightly compressed, usually bristly and enclosing the nectary and style with spines; mericarp with 5 filiform primary ribs and 4 stouter secondary ribs usually with a single row of bristles; carpophore persistent, entire or bifid.
About 60 species, cosmopolitan; 1 native and 2 or 3 naturalised species in Australia.