Burke: Rubus ulmifolius vs. Rubus ursinus

	Rubus ulmifolius	Rubus ursinus
	elm-leaf blackberry	Pacific blackberry, trailing blackberry, dewberry, Douglasberry
Habit		Dioecious perennial with slender, trailing stems up to 6 m. long, abundantly armed with slender, hooked prickles.
Leaves		Leaves trifoliate, the lateral leaflets ovate-lanceolate, 3-7 cm. long, doubly serrate; terminal leaflet larger, deeply 3-lobed.
Flowers		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.
Fruits		Drupelets purplish-black, coherent, attached to the elongate receptacle; fruit up to 2.5 cm. long.

	Rubus ulmifolius	Rubus ursinus
Flowering time	May-July	April-August
Habitat	Fields, thickets, forest edge, and other disturbed areas.	Open to fairly dense woodlands, thickets, and balds, sea level to middle elevations in the mountains; common in logged areas.
Distribution	Occurring west of the Cascades crest in Washington; southwestern British Columbia to California and Nevada; also in New Jersey. [WildflowerSearch map] [BONAP county map]	Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, east to Montana. [WildflowerSearch map] [BONAP county map]
Origin	Introduced Europe and northern Africa	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	R. allegheniensis, R. arcticus, R. bifrons, R. idaeus, R. laciniatus, R. lasiococcus, R. leucodermis, R. nigerrimus, R. nivalis, R. parviflorus, R. pedatus, R. pensilvanicus, R. pubescens, R. spectabilis, R. ursinus, R. vestitus	R. allegheniensis, R. arcticus, R. bifrons, R. idaeus, R. laciniatus, R. lasiococcus, R. leucodermis, R. nigerrimus, R. nivalis, R. parviflorus, R. pedatus, R. pensilvanicus, R. pubescens, R. spectabilis, R. ulmifolius, R. vestitus
Web links	Local floras: CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Rubus ursinus

elm-leaf blackberry

Pacific blackberry, trailing blackberry, dewberry, Douglasberry

Habit

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

Leaves

Leaves trifoliate, the lateral leaflets ovate-lanceolate, 3-7 cm. long, doubly serrate;

terminal leaflet larger, deeply 3-lobed.

Flowers

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.

Fruits

Drupelets purplish-black, coherent, attached to the elongate receptacle;

fruit up to 2.5 cm. long.