Helianthus silphioides is a North American species of sunflower known by the common names rosinweed sunflower or Ozark sunflower. It is native to the central United States, primarily in the Ozarks and the Tennessee Valley with additional populations north into Kentucky and Illinois and south as far as Louisiana, Mississippi and Alabama.Biota of North America Program 2014 county distribution map
Helianthus silphioides grows in open locations. It is a perennial herb up to 300 cm (10 feet) tall. Leaves are broadly egg-shaped. One plant usually produces 3-15 flower heads, each containing 8–13 yellow ray florets surrounding 75 or more red disc florets.Flora of North America, Helianthus silphioides Nuttall, 1841. Rosinweed sunflower
A 2004 Illinois conservation assessment listed Helianthus silphioides as critically imperiled within the state.Molano-Flores 2004 The species is also considered endangered within Kentucky,Jones 2005 likely due to habitat loss of open oak woodlands and barrens. Throughout the remained of its range, it is considered apparently secure or conservation status is unknown.Molano-Flores 2004
References
External links Photo of herbarium specimen at Missouri Botanical Garden, collected in Missouri in 1992 Ozark Edge Wildflowers