Annual or short-lived perennial herbs; branches decumbent to ascending, 0.2-5(-l) m long, glabrate to pubescent. Leaf blades reniform-orbicular, usually 2-8 cm wide, shallowly 3-lobed, 5-lobed, or 7- lobed, margins undulate, crenate. Flowers solitary or few in dense cymes, greatly exceeded by the leaves, pedicels filiform, up to 1 (-2.5) cm long in fruit; involucral bracts filiform to linear, 1-4 mm long; calyx 3-5 mm long, accrescent in fruit, spreading, up to 15 mm in diameter, scarious, veiny; petals lavender blue, scarcely exceeding the calyx. Mericarps 10-11, up to 2.3 mm high and 3 mm wide, with reticulate-rugose walls and acute, slightly winged margins, indehiscent. Seeds ca. 1.8 mm long, glabrous. [2n = 40-44.] Native from the Mediterranean region through Asia Minor to India, an introduced weed in many regions of the world; in Hawai‘i naturalized primarily in disturbed areas, 0-2,270 m, on French Frigate Shoals and all of the main islands. Apparently first collected by Lay and Collie on 0‘ahu or Ni‘ihau in 1826 or 1827 (Degener & Degener, 1960d).