Page authors: Don Knoke, David Giblin
Oxalis trilliifolia
great wood-sorrel, trillium-leaf wood-sorrel

Distribution: West slope of the Cascades in Washington; Washington south to northwest California.

Habitat: Meadows and moist woods in the coastal mountains and up to 6000 feet in the Cascades.

Flowers: May-August

Origin: Native

Conservation Status: Not of concern


Acaulescent perennials with stout, scaly rhizomes.


Petioles 5-20 cm. long, usually with soft, brownish hairs; leaves trifoliate, the leaf blades 5-8 cm. broad, obovate with a wedge-shaped base.


Scapes 3- to 7-flowered; sepals 5, persistent; petals 5, about 1 cm. long, white or tinged with pink, shallowly notched; stamens 10, united basally, of 2 unequal lengths; styles 5, the stigmas capitate.


Capsule linear, 2-3 cm. long, with a slender beak

Accepted Name:
Oxalis trilliifolia Hook.
Publication: Flora Boreali-Americana 1(3): 118. (as trilliifolium). 1831.

Synonyms & Misapplications:
Hesperoxalis trilliifolia (Hook.) Small
Additional Resources:

PNW Herbaria: Specimen records of Oxalis trilliifolia in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Oxalis trilliifolia checklist entry.

E-Flora BC: Oxalis trilliifolia atlas page.

CalPhotos: Oxalis trilliifolia photos.

USDA Plants: Oxalis trilliifolia information.

10 photographs:
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