California Blackberry

Rubus ursinus

Also known as: Pacific Dewberry

USFWS - Pacific Region

Taxonomy

Division:: Magnoliophyta | - Flowering plants
Family:: Rosaceae
Genus:: Rubus
Species:: Rubus ursinus

Growth Characteristics

Life Cycle:: Perennial
Growth Habit:: Subshrub
Height:: 4-6 ft
Light Requirements:: Full Sun, Part Shade, Shade
Drought Tolerance:: Medium
Bloom Months:: mar, apr, may, jun, jul
Bloom Colors:: White, Pink

Native Range

United States: California, Idaho, Montana, Oregon, Washington, Canada: British Columbia

Keystone Species Ranking

Caterpillar Keystone:: ★☆☆☆☆ Based on number of butterfly and moth species using this genus as host plant (Source: National Wildlife Federation)

Host Plant for Caterpillars

Acleris keiferi, blackberry skeletonizer (Schreckensteinia festaliella), Britannia Acleris Moth (Acleris britannia), Marmara sp., orange tortrix moth (Argyrotaenia citrana), orange tortrix moth (Argyrotaenia franciscana), Tischeria splendida

Reported Fauna Sightings

Bees: Black-tailed bumble bee (Bombus melanopygus), Black-tailed bumble bee (Bombus melanopygus), Fuzzy-horned bumble bee (Bombus mixtus), Fuzzy-horned bumble bee (Bombus mixtus), Obscure bumble bee (Bombus caliginosus), Obscure bumble bee (Bombus caliginosus), Sitka bumble bee (Bombus sitkensis), Sitka bumble bee (Bombus sitkensis), Yellow head bumble bee (Bombus flavifrons), Yellow head bumble bee (Bombus flavifrons), Yellow-faced bumble bee (Bombus vosnesenskii), Yellow-faced bumble bee (Bombus vosnesenskii)

Soil Requirements

Soil Type:: rich, well-drained loamy soil
pH:: 5.5 - 7.0 (slightly acidic to neutral)
Drainage:: excellent drainage required
Moisture:: consistently moist
Notes:: thrives in forest edges and clearings

Germination Information

Pre-treatment: For seeds, sow into trays filled with stabilized medium plugs (Q-plugs) and refrigerate at 1 to 3 °C for 120 days. For cuttings, dip in a mild bleach solution for 30 seconds, recut to 5 inch lengths of 4 nodes each, and treat with Hormex (3000 ppm IBA) rooting powder.

Establishment: R. ursinus is found mostly below 3,000 feet elevation in canyons and waste places; from Oregon to Lower California. Seeds are collected between June and August. Hardwood cuttings are collected between December 15th and January 31st. There are variations in the pre-treatment and establishment protocols between seeds and cuttings.

Source: npn.rngr.net