Plant: Plant 5-15 dm; stem prostrate to erect, hollow, not rooting at nodes Leaves: opposite; petiole 0.3-2.5 cm; blade 7-18 cm, oblong to obovate, leaflets 2-4.5 cm, ovate to ± round, generally lobed Inflorescence: umbels compound, peduncled or not; bracts, bractlets conspicuous to 0; rays 7-16, 0.7-2.5 cm, subequal Flowers: many, small, calyx lobes minute; petals 5, wide, free, white or greenish white; stamens 5; pistil 1, ovary inferior, 2-chambered, generally with a ± conic, persistent projection or platform on top subtending 2 free styles, projection sometimes flat Fruit: 2 dry, 1-seeded halves that separate from each other but generally remain attached for some time to a central axis, 1.5-2 mm diam, elliptic to nearly round; fruit axis notched at tip compressed side-to-side; ribs subequal, thread-like to obtuse and corky; oil tubes per rib-interval 1; fruit axis entire or notched at tip; Seed: face flat Misc: Wet places; generally < 1000 m.; May-Jul References: Kearney and Peebles, Arizona Flora. McDougall, Seed plants of Northern Arizona. ASU specimans.