Plants annual, glabrous except the fruit. Leaves 2-3-pinnate; segments filiform. Involucre of long linear or ternate bracts. Rays 3-6. Involucel of linear bractlets. Calyx teeth subulate, unequal. Petals white or rose coloured. Fruit oblong, setulose or villous; secondary ridges equal to or more prominent than the primary ridges. Inner seed face concave.