Distribution: Occurring in southwest Washington; south in Willamette Valley of Oregon from Portland to Salem, west to Tillamook County.
Habitat: Gravelly, well-drained soil at low elevations.
Flowers: May-July
Origin: Native
Conservation Status: Endangered in Washington (WANHP)
Herbaceous perennial from a stout taproot and short rhizome, glabrous to pubescent with short, stiff, appressed, simple hairs.
Leaves alternate, palmately veined, long petiolate, the lower rotund, shallowly lobed, the lobes with coarse, rounded teeth, the upper with 5-7 lobes to the base, the lobes linear and pointed.
Inflorescence an elongate, narrow raceme, many-flowered, the pedicels about 3 mm. long; calyx 5 lobed, 4-6 mm. long, purplish-tinged, sub-glabrous to thickly pubescent with stellate hairs; petals 5, pinkish-lavender, 5-15 mm. long, clawed, broadly obovate and notched; stamens 40-70, freed from the staminal tube in 2-3 series, the stamens united in groups; ovary superior, the carpels 5-10 in a ring around a central axis; styles equal to the number of carpels, elongate, stigmatic full length.
Fruit: Capsule 3 mm. long, with a beak less than 0.5 mm. long.
PNW Herbaria: Specimen records of Sidalcea nelsoniana in the Consortium of Pacific Northwest Herbaria database.
WA Flora Checklist: Sidalcea nelsoniana checklist entry.
E-Flora BC: Sidalcea nelsoniana atlas page.
CalPhotos: Sidalcea nelsoniana photos.
USDA Plants: Sidalcea nelsoniana information.