Page authors: Ben Legler, David Giblin
Marah oregana
coastal manroot

Distribution: Occurring chiefly west of the Cascades crest and east in the Columbia River Gorge in Washington; British Columbia to California, also rarely in Hells Canyon in Idaho.

Habitat: Low elevation fields, thickets and open areas.

Flowers: April-June

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Bees, flies


Perennial vine from a large, woody, tuberous root; stems herbaceous, leafy, bearing tendrils.


Alternate, to 20 cm long, shallowly lobed and cordate at base.


White, 6-12 mm across with 5 flaring lobes (or sometimes 6-8); male flowers in racemes, female flowers mostly single in axil at base of racemes.


Green, weakly spiny, inflated gourd-like fruits 3-8 cm long with several large seeds inside.

Identification Notes:

Look for the mostly 5-lobed white flowers and inflated gourd-like fruits. Compare with grapes (family Vitaceae) which have woody stems and more mumerous minute unshowy flowers.

Accepted Name:
Marah oregana (Torr. & A. Gray) Howell
Publication: A Flora of Northwest America 2: 239. 1898.

Synonyms & Misapplications:
Marah oreganus (Torr. & A. Gray) Howell, orthographic variant [HC]
Additional Resources:

PNW Herbaria: Specimen records of Marah oregana in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Marah oregana checklist entry

OregonFlora: Marah oregana information

E-Flora BC: Marah oregana atlas page

CalPhotos: Marah oregana photos

48 photographs:
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