Rocky Mountain cutleaf coneflower

Rudbeckia ampla A. Nelson, Bull. Torrey Bot. Club 28: 234. 1901

Leaves: basal 20–50 × 10–25 cm, blades pinnately compound to pinnatifid (basal leaflets or lobes often pinnatifid); proximal and mid cauline blades 5–9-lobed; adaxial faces glabrous or sparsely hairy (hairs arching, 1-seriate). Receptacles ovoid; paleae 4.5–6.5 mm. Ray laminae 25–50 × 7–12 mm. Discs (17–)20–30 × 12–20 mm. Cypselae 4–5.5 mm; pappi mostly longer than 0.7 mm. 2n = 38.

Flowering summer–fall. Wet sites, along streams, open meadows; 1700–2700 m; B.C.; Ariz., Colo., Mont., N.Mex., S.Dak., Wyo.

Variety ampla grows west of the Great Plains. It is introduced in British Columbia.