Asclepias engelmanniana
(Englemann's Milkweed)
Family: Asclepiadaceae (Milkweed)
    
Asclepias engelmanniana is a tall, slender plant with narrow, linear leaves. Flowers are green with purple tips.  A. engelmanniana grows on sandy, rocky or calcareous soils on the plains and foothills.

Vegetation zone:  Plains, Foothills  (3700 - 6500 ft.)
Time of bloom:  June - August
Origin:  Native
Eastern Colorado Wildflowers