Plants 25–40(–80) cm. Basal leaves: blades (light green) lance-elliptic to elliptic-ovate, (10–)20–30+ cm, margins usually entire, sometimes denticulate, ± ciliolate, faces sparsely pilose to pilosulous (usually minutely gland-dotted or stipitate-glandular as well); cauline leaves similar, smaller distally (petiolate or sessile). Heads borne singly. Involucres ± hemispheric, (12–)20–30(–40) mm diam. Phyllaries 36–48, subequal, herbaceous, margins villous-ciliate, faces glabrous or glabrate; outer 18–25 mm (not surpassing discs). Ray florets 13–25; laminae (cream to white) 25–45 mm. Cypselae 9–11 mm, strigillose distally and on margins.
Phenology
may (spring), jun-jul (summer)
Altitude range
40–2600 m;
Distribution
USA IdahoUSA Mont.USA Nev.USA Oreg.USA Wyo.
Discussion
Hybrids between Wyethia helianthoides and W. amplexicaulis are infrequent where the species are in contact; no introgression has been noted. The hybrids have been called Wyethia ×cusickii Piper; they usually bloom later than W. helianthoides and earlier than W. amplexicaulis.