Page authors: Don Knoke, David Giblin
Rubus ursinus
Pacific blackberry, trailing blackberry, dewberry, Douglasberry

Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, east to Montana.

Habitat: Open to fairly dense woodlands, thickets, and balds, sea level to middle elevations in the mountains; common in logged areas.

Flowers: April-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Apomixis, bumblebees, bees, beetles


Dioecious perennial with slender, trailing stems up to 6 m. long, abundantly armed with slender, hooked prickles.


Leaves trifoliate, the lateral leaflets ovate-lanceolate, 3-7 cm. long, doubly serrate; terminal leaflet larger, deeply 3-lobed.


Floral branches several, 1-3 dm. long, erect, bearing several leaves and 1-several flat-topped flower clusters, the inflorescence with stalked glands; calyx hairy and glandular, the 5 lobes lanceolate, 5-11 mm. long; staminate petals 5, white, elliptic-spatulate, 7-11 mm. long, with 75-100 stamens; pistillate petals broader and shorter, with numerous pistils.


Drupelets purplish-black, coherent, attached to the elongate receptacle; fruit up to 2.5 cm. long.

Accepted Name:
Rubus ursinus Cham. & Schltdl.
Publication: Linnaea 2: 11. 1827.

Synonyms & Misapplications:
Rubus eastwoodianus Rydb.
Rubus helleri Rydb.
Rubus macropetalus Douglas ex Hook.
Rubus ursinus Cham. & Schltdl. ssp. macropetalus (Douglas ex Hook.) Roy L. Taylor & MacBryde
Rubus ursinus Cham. & Schltdl. var. eastwoodianus (Rydb.) J.T. Howell
Rubus ursinus Cham. & Schltdl. var. macropetalus (Douglas ex Hook.) S.W. Br. [HC]
Rubus vitisolius ssp. ursinus Abrams
Additional Resources:

PNW Herbaria: Specimen records of Rubus ursinus in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Rubus ursinus checklist entry.

OregonFlora: Rubus ursinus information.

E-Flora BC: Rubus ursinus atlas page.

CalPhotos: Rubus ursinus photos.

USDA Plants: Rubus ursinus information.

58 photographs:
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