Herbs, perennial, (0.3–)0.4–1.5 m, glaucous or not, with short, thick, rather woody taproot and branching caudex, without rhizomes or rhizomelike rootstocks (subsp. valida sometimes with rhizomes). Stems single or clustered, erect, rarely rooting at base, unbranched or distally branched, proximally usually solid, sometimes hollow in age, base glabrous, coarsely stellate-hairy to long-bristly, or glabrate, hairs usually becoming appressed, simple or stellate. Leaves basal and cauline, basal sometimes deciduous, cauline 3+; stipules usually deciduous, linear to lanceolate, 4–6(–14) × 0.5–1(–2) mm; petioles of basal and proximal leaves (5–)7–10(–35) cm, 3–5 times as long as blades, reduced distally, distalmost leaves sometimes subsessile; blade cordate or reniform-orbiculate, 3–10(–15) × 3–10(–15) cm, base cordate, apex rounded, lobe apex often acute, surfaces glabrous or sparsely hairy, hairs minute, simple, forked, or stellate, proximal usually shallowly palmately 5–7(–9)-lobed, sometimes unlobed with margins crenate; midstem more deeply (3–)5–9-lobed, lobes again palmately or pinnately lobed, distalmost unlobed or 3(–5)-lobed, segments unlobed or deeply lobed, narrow. Inflorescences erect, usually spiciform, sometimes subcapitate, congested in bud, dense, calyces sometimes conspicuously overlapping in flower and sometimes in fruit, to open and elongate, few-branched or unbranched, 10–20+-flowered, flowers opening and closing sequentially from base to apex, sometimes 3–10 open on same day, not leafy-bracted, not 1-sided, (1.5–)10–30 cm, elongating in flower or fruit; bracts linear to linear-lanceolate, undivided to 2-fid, proximal sometimes divided to base, 4–6(–7) mm, sometimes exceeding flower buds, usually equaling or longer than pedicels, shorter than calyx. Pedicels 1–3(–10) mm; involucellar bractlets absent. Flowers bisexual or unisexual and pistillate, plants gynodioecious; calyx usually green, 3.5–10 mm, usually lightly reticulate-veined, glabrous or densely, uniformly stellate-puberulent or bristly, surface often obscured; petals usually overlapping, pink or pink-lavender to dark rose-pink or magenta, not notably pale-veined, pistillate 5–10 mm, bisexual 8–15(–20) mm; staminal column 4–6(–9) mm, hairy; anthers white to pinkish; stigmas 6–9. Schizocarps 4–7 mm diam.; mericarps 6–9, 2–3 mm, sparsely glandular-puberulent, sometimes glabrous, not stellate-hairy, back and margins rounded, smooth or slightly reticulate-veined or pitted, infrequently prominently roughened at least on margins and/or back, mucro 0.1–0.7 mm. Seeds 1.5–2.5 mm. 2n = 20, 40, 60.
B.C., Calif., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.
Subspecies 5 (5 in the flora).
Sidalcea oregana is variable and parts of it have been treated as distinct species, subspecies, varieties, or extremes of a continuum. The plants are generally characterized by their strictly erect, leafless inflorescences that are congested in bud, their variable, sparsely hairy, lobed leaves that are both basal and cauline, and their usual lack of rhizomes. They often have been characterized and distinguished from the S. malviflora group by smooth mericarps; this feature depends upon the subspecies and is not true of all plants of S. oregana. These are usually mountain plants; some grow at lower elevations toward the northern parts of the range.
|1||Primary peduncles (distal to distalmost leaves) longer than mature inflorescence; inflorescences dense, short-spiciform or subcapitate, 1.5–5 cm in age; calyces usually stellate-puberulent with sparse or no bristles; usually wetlands; California, Nevada||> 2|
|1||Primary peduncles usually equaling or shorter than mature inflorescence; inflorescences open or dense, spiciform, 3–30 cm in age; calyces stellate-puberulent, with or without longer bristle hairs 0.5–2.5 mm; meadows, prairies, streamsides, not characteristically wetlands; British Columbia to California, Montana, Nevada, Utah, Wyoming||> 3|
|2||Stems to 5 mm diam. near base, base stellate-bristly or hirsute, bristle hairs 2 mm; inflorescences 1.5–2.5 cm; 1100–2300 m.||Sidalcea oregana subsp. hydrophila|
|2||Stems 5–10 mm diam. near base, base usually bristly-hirsute, sometimes with minute stellate hairs, bristle hairs 1–1.5 mm; inflorescences 2–5 cm; 100–200 m.||Sidalcea oregana subsp. valida|
|3||Calyces to 8–13 mm in fruit, bristly-tomentose, some hairs 1.5–2.5 mm; Humboldt County, California.||Sidalcea oregana subsp. eximia|
|3||Calyces to 3.5–7(–10) mm in fruit, short-stellate-hairy, sometimes also with bristles but not bristly-tomentose; British Columbia to California, Montana, Nevada, Utah, Wyoming||> 4|
|4||Stem bases glabrous or stellate-hairy, hairs usually to 1 mm, sometimes bristly with appressed hairs, infrequently spreading; calyces usually uniformly stellate-puberulent; bracts usually shorter than young flower buds; rachis apex usually blunt or rounded.||Sidalcea oregana subsp. oregana|
|4||Stem bases usually softly bristly-hirsute with hairs 1–2 mm or stellate-hairy, sometimes glabrous; calyces usually densely stellate-hairy, sometimes bristly; bracts usually longer than young flower buds; rachis apex usually acute.||Sidalcea oregana subsp. spicata|