Rudbeckia laciniata var. ampla

(A. Nelson) Cronquist

in C. L. Hitchcock et al., Vasc. Pl. Pacif. N.W. 5: 280. 1955.

Common names: Rocky Mountain cutleaf coneflower
Basionym: Rudbeckia ampla A. Nelson Bull. Torrey Bot. Club 28: 234. 1901
Treatment appears in FNA Volume 21. Treatment on page 49.

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.

Phenology: Flowering summer–fall.
Habitat: Wet sites, along streams, open meadows
Elevation: 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.

Selected References


Lower Taxa

Lowell E. Urbatsch +  and Patricia B. Cox +
(A. Nelson) Cronquist +
Rudbeckia ampla +
Rocky Mountain cutleaf coneflower +
B.C. +, Ariz. +, Colo. +, Mont. +, N.Mex. +, S.Dak. +  and Wyo. +
1700–2700 m +
Wet sites, along streams, open meadows +
Flowering summer–fall. +
in C. L. Hitchcock et al., Vasc. Pl. Pacif. N.W. +
Rudbeckia subg. Macrocline +
Rudbeckia laciniata var. ampla +
Rudbeckia laciniata +
variety +