Asclepias viridiflora (Green Milkweed)
Family: Asclepiadaceae (Milkweed)
Asclepias viridiflora grows on dry sites on the plains and lower foothills. Flowers are green with reflexed petals. Plants are often sprawling on the ground. Leaves vary from oval with wavy margins (2nd photo) to lanceolate with a long narrowing blade (3rd photo).

Vegetation zone:  Plains, Foothills  (3500 - 7000 ft.)
Time of bloom:  June - August
Origin:  Native
Eastern Colorado Wildflowers