Plant: Erect annual forb 10-20 cm; herbage with milky sap; stems delicate Leaves: cauline, opposite, short-petioled, linear, 1-2 cm long, with revolute margins; tip acute to obtuse INFLORESCENCE: involucre < 1.5 mm, obconic, glabrous; gland < 0.5 mm, round, appendage wider than gland or 0, entire, white Flowers: flowers monoecious borne in cyathia; petaloid appendages white; Staminate flowers 5-10, generally in 5 clusters around pistillate flower, each flower a stamen; Pistillate flower: 1, central, stalked; ovary chambers 3, ovule 1 per chamber, styles 3, divided 1/2 length Fruit: capsule slightly < 1.5 mm, spheric, lobed, glabrous; Seeds 1-1.5 mm, ovoid, 3-angled, white with transverse wrinkles Misc: Rocky slopes; < 3100 m.; Aug-Sep