2a. var. flavum S.F. Blake

Stems and leaves green, usually not purple-tinged. Petals bright yellow. 2n=22. April–June.

Scattered nearly throughout the state, but more common south of the Missouri River (eastern U.S. west to Minnesota and Texas; Canada). Mesic to dry upland forests, upland prairies, savannas, glades, ledges and tops of bluffs, and less commonly banks of streams; also old fields, roadsides, and railroads.