Helianthus pumilus is a North American species of sunflower known by the common name little sunflower or bush sunflower.United States Department of the Interior, National Park Service, Rocky Mountain National Park, Bush Sunflower helianthus pumilus It is found in the western United States, primarily the Rocky Mountain region of Montana, Wyoming, and Colorado, with a few isolated populations in Utah and Idaho.Biota of North America Program 2014 county distribution map
Helianthus pumilus grows on dry rocky soil in the mountains and nearby plains. It is a perennial herb up to 100 cm (40 inches) tall. One plant usually produces 1–6 flower heads, each containing 8–13 yellow ray florets surrounding 30 or more yellow or brown disc florets.Flora of North America, Helianthus pumilus Nuttall, 1841. Little sunflower Nuttall, Thomas 1841. Transactions of the American Philosophical Society, new series 7: 366–367
References
External links Eastern Colorado Wildflowers photos Lady Bird Johnson Wildlower Center, University of Texas