Helianthus nuttallii (Nuttall's Sunflower)
Family:
Asteraceae (Sunflower)
        
Helianthus nuttalli grows on moist sites near the base of the foothills. It is a tall plant, growing to over 6 feet tall. Leaves are long, narrowly lanceolate and often have a few small teeth. Below the flower are several rows of long, narrow wavy phyllaries.

Vegetation zone:  Plains, Foothills
Time of bloom:  July - September
Origin:  Native
Eastern Colorado Wildflowers