Usually annual, rarely perennial herbs, glabrous or hairy. Leaves entire or 3-5-lobed. Flowers showy, red, purple or white; epicalyx segments 3, large, free, cordate, triangular or ovate-cuneate. Calyx 5 lobed. Petals 5. Staminal tube divided into numerous filaments. Carpels numerous, irregularly arranged around the style in many whorls; locule 1-ovuled; style as many as carpels. Fruit a schizocarp; mericarps separating, indehiscent. Seed 1 in each mericarp.