Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east across much of North America to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed areas where often escaped from cultivation.
Flowers: May-August
Origin: Introduced from Eurasia
Growth Duration: Perennial
Conservation Status: Not of concern
Pollination: Bees, wasps
Glabrous perennial, the stems 1.5-3 dm. tall, simple below but freely branched above.
Leaves alternate, the lower ones linear, 1-3 cm. long and 1-3 mm. broad; leaves of the axillary upper branches more numerous and narrower.
Inflorescence a many-rayed umbel, the floral bracts broadly ovate-cordate, 12-16 mm. long; flowers tiny, monoecious, borne in involucres; staminate flowers numerous, naked, each consisting of a single stamen; pistillate flower single and terminal in the involucre; involucres about 3 mm. long, bearing 4 reddish-green, horned glands.
Capsules finely warty, separating into three 1-seeded segments.
PNW Herbaria: Specimen records of Euphorbia cyparissias in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Euphorbia cyparissias checklist entry
OregonFlora: Euphorbia cyparissias information
E-Flora BC: Euphorbia cyparissias atlas page
CalPhotos: Euphorbia cyparissias photos