Annual herb, 15-40cm, covered with gland-tipped hairs. Leaves lobed and toothed, margins sometimes rolled under; bears clusters of radiate flowerheads with mauve or white rays and a yellow disc; the involucre is cylindrical and covered with fine gland-tipped hairs.

Latin: arena = sandy place, sandy desert, -arius, indicates connection: referring to this species habit of growing in sand.