Rubus ursinus Cham. & Schltdl., Linnaea 2:11. 1827 (syn: Parmena menziesii (Hook.) Greene; Rubus menziesii Hook.; Rubus ursinus var. glabratus C.Presl; Rubus ursinus var. menziesii (Hook.) Focke; Rubus ursinus subsp. ursinus ; Rubus ursinus var. ursinus ; Rubus vitifolius subsp. ursinus (Cham. & Schltdl.) Abrams);
USA (California, Oregon), Mexico (Baja California Norte), Australia (I) (New
South Wales (I)) as per Catalogue of Life;
Rubus ursinus is a North American species of blackberry or dewberry, known by the common names California blackberry, California dewberry, Douglas berry, Pacific blackberry, Pacific dewberry and trailing blackberry.
The name is from rubus for “bramble” and ursinus for “bear.”
Rubus ursinus is a wide, mounding shrub or vine, growing to 2–5 feet (0.61–1.52 m) high, and more than 6 feet (1.8 m) wide.  The prickly branches can take root if they touch soil, thus enabling the plant to spread vegetatively and form larger clonal colonies.
Leaves usually have 3 leaflets but sometimes 5 or only 1, and are deciduous. The plant is dioeocious, with male and female plants on separate plants, also unusual for the genus. As with other Rubus, the canes are typically vegetative the first year, and reproductive in the second.
Flowers are white with narrower petals than most related species, and have a fragrance.  The sweet, very aromatic, edible fruits are dark purple, dark red, or black and up to 2 centimeters (0.8 inches) in length.
Rubus ursinus is cultivated for its fruit, and also ornamental plant qualities.  It is planted in home, native plant, and wildlife gardens, and in natural landscaping projects.  It can be espaliered or trained on fences and trellising.  When mature/established, the plant is effective in stabilizing creek banks and edges of bioswales.
To set large fruit, the plant needs consistent amounts of moisture. Otherwise it is moderately drought tolerant when established. Seed size seems to be related to fruit “cell” size, and the smallest (1 cm) fully formed berries are most highly prized. These are sometimes called “little wild blackberries.”
(From Wikipedia on 24.9.15)
Rosaceae Fortnight: Rubus ursinus from California-GSSEP108/108 : 1 post by 1 author. Attachments (2)
Photographed from California