Native plant identification key for the
Palos Verdes Peninsula, California


Leaflets ovate (egg-shaped, wider toward the base) to cordate (heart-shaped, wider at the base), margins irregularly serrate (jagged with teeth pointing toward the tip), ~2-10 cm long (the outermost, single leaflet usually a little larger than the others), ~1.5-2.5 cm wide, petioles (leaf stalk) and rachis (central stem inside the leaf, to which the leaflets attach) are prickly, ~2-6 cm long, with a pair of linear stipules winging the base of the petiole. Leaflets are hairy, green top and bottom, and are retained all year. Stems are very prickly (which helps differentiate it from poison oak). Plant is generally dioecious (flowers are unisexual and the sexes are segregated on different plants) Flowers have 5 ovate to narrowly obovate (egg-shaped, wider toward the tip) petals ~0.5-2.5 cm long, white. Staminate (male) flowers have dozens of stamens, and pistillate (female) flowers have many pistils. There are 5 pointed and tomentose (woolly) sepals. The flowers are usually carried in clusters (cymes) with a few flowers per cluster, each on prickly pedicels (small stems). Blooms March to July. Fruit is a fused collection of small black or dark purple drupelets, each ~0.1-0.2 cm diameter and containing one small soft pit, usually glabrous (smooth), and in an oblong or conical spike ~2 cm long: a blackberry. Plant itself is a densely branched and thicket-forming shrub or vine that climbs on top of other plants or mounds up into a bramble patch on the ground, ~1-2 m tall and often much wider. Favors fairly moist places, such as in canyons and along streams and washes and in the shade of taller shrubs and trees. Found throughout California (and up into the Pacific Northwest into British Columbia and Idaho) below 1500 m, except in the deserts of eastern California.

Rubus ursinus aka R. vitifolius aka R. macropetalus aka R. vitifolius var. vitifolius aka R. vitifolius var. titanus aka R. vitifolius var. eastwoodianus aka R. lemurum aka R. eastwoodianus (Rosaceae): California blackberry or Pacific blackberry


First placed on web: 08/09/11
Last revised: 08/09/11
Christine M. Rodrigue, Ph.D., Department of Geography, California State University, Long Beach, CA 90840-1101
rodrigue@csulb.edu

The development of this key was partially funded through the Geoscience Diversity Enhancement Program (Award #0703798) and through a course of re-assigned time provided by the CSULB Scholarly and Creative Activities Committee. Thanks also to the students in sections of biogeography, introductory physical geography, GDEP, and LSAMP for "test-driving" various editions of this key.