Perennials, 15-60(-100) cm (taproots relatively massive; caudices seldom branched).
Stems erect (or bending erect from bases), branched mostly from bases.
Leaves basal and cauline; alternate; usually petiolate (basal), sometimes sessile; blades (usually pinnately nerved, basal larger than cauline) ± deltate, elliptic-ovate, lanceolate, lance-elliptic, lance-linear, or oblong-ovate, bases truncate to cuneate, margins usually entire, rarely dentate to serrate (sometimes ciliate), faces glabrous or hairy (sometimes gland-dotted or finely stipitate-glandular).
Heads radiate, borne singly or 2-5(-8+) in ± corymbiform to racemiform arrays.
Involucres hemispheric to campanulate or turbinate, 12-60+ mm diam.
Phyllaries persistent, 12-36(-48) in 2-3+ series (subequal to unequal, outer sometimes foliaceous, much larger than inner).
Receptacles flat to convex, paleate (paleae conduplicate, at least bases, papery).
Ray florets 5-25+, pistillate, fertile; corollas mostly yellow (cream to white in
W. helianthoides).
Disc florets 35-150+, bisexual, fertile; corollas yellow, tubes much shorter than cylindric throats; lobes 5, ± deltate to lanceolate (style branches stigmatic in 2 barely distinct lines, appendages ± filiform).
Cypselae ± prismatic, weakly 3-4-angled (faces glabrous or hairy);
pappi 0, or persistent, coroniform (usually lacerate) or of 1-4+ ovate to subulate, erose to lacerate (often basally connate) scales.
x = 19. Some species formerly included in
Wyethia are here treated in
Agnorhiza and
Scabrethia.
Balsamorhiza is closely related to
Wyethia.