Plant: Shrub, sometimes tree-like, 1-3 m, monoecious, ± glabrous; sap clear; stem: trunk ascending to erect, branched above Leaves: simple, cauline, alternate, peltate; stipules fused, 1-1.5 cm, sheath-like, deciduous; petiole 1-3 dm, glandular distally; blade 1-5 dm, ± round, palmately 7-11-lobed, sharply toothed INFLORESCENCE: panicle, terminal, 1-3 dm; staminate flowers below pistillate flowers Flowers: Staminate flower: sepals 3-5; petals 0; stamens many, clustered; nectary 0; Pistillate flower: sepals 3-5; petals 0; ovary 3-chambered, bristly, styles 2-lobed, plumose, reddish Fruit: capule, 1.2-2 cm diam, ± spiny; Seed 9-22 mm, smooth, shiny, mottled; scar appendaged. 2n=20 Misc: Disturbed areas, fields, roadsides; < 300 m.