Rubus ursinus
Rubus bartonianus
California blackberry, California or Pacific or creeping blackberry, dewberry, Douglasberry, dwarf red raspberry, Pacific blackberry, Pacific dewberry, Pacific trailing blackberry, salmonberry, trailing blackberry
Barton's raspberry, bartonberry
biennial, creeping (often growing over other vegetation), sparsely to densely hairy, eglandular or sparsely to densely sessile- to stipitate-glandular, usually strongly pruinose;
prickles moderate to dense, erect to retrorse or hooked, weak to moderately stout, 4–10 mm, narrow- to broad-based.
erect, sparsely short-hairy, glabrescent, eglandular, not pruinose.
deciduous or persistent, usually ternate, sometimes simple or pinnately compound;
stipules filiform to linear, 7–17 mm;
leaflets 3(–5), terminal ovate to lanceolate, 3.5–12 × 3–10 cm, base cuneate or rounded to cordate, shallowly sharp-lobed or unlobed, margins coarsely serrate to doubly serrate, apex acute to acuminate, abaxial surfaces with slender, erect prickles on larger veins, moderately to densely hairy, eglandular, rarely sparsely sessile-glandular along midvein.
deciduous, simple;
stipules lanceolate, 4–6 mm;
blade cordate to broadly ovate, (2–)2.5–4(–5) × (2.5–)3.5–4.5(–5.5) cm, base deeply cordate, 3–5-lobed, lobe apices acute to obtuse, margins coarsely doubly dentate, abaxial surfaces glabrous or sparsely hairy, eglandular or sparsely stipitate-glandular.
terminal on short shoots, usually appearing axillary, 1–5-flowered, cymiform or racemiform.
1-flowered.
prickles moderate to dense, erect, densely hairy, eglandular or sparsely to densely stipitate-glandular.
moderately hairy, eglandular or sparsely stipitate-glandular.
usually functionally unisexual;
petals white, in staminate flowers ovate or obovate to narrowly elliptic, 7–18 mm, in pistillate ovate to elliptic, 6–11 mm;
filaments filiform;
ovaries glabrous or hairy.
bisexual;
petals white, obovate, (15–)20–25 mm;
filaments filiform;
ovaries glabrous, styles clavate, villous.
black, sometimes red or purple, rarely white, not pruinose, globose to cylindric, 1–2.5 cm;
drupelets 20–50, strongly coherent, separating with torus attached.
deep red, hemispheric, to 1 cm;
drupelets 10–30, coherent, separating from torus.
= 42, 56, 63, 70, 77, 84, 91.
Rubus ursinus
Rubus bartonianus
In habit, Rubus ursinus is often reminiscent of the predominantly eastern North American, non-sympatric R. flagellaris; it is also polymorphic. Rubus ursinus comprises a polyploid spectrum dominated by octoploid and dodecaploid plants. It is an allopolyploid involving phylogenetically distant ancestors with its closest relative being the Hawaiian endemic R. macraei A. Gray. See S. W. Brown (1943) for a discussion of morphological and chromosome number variation in R. ursinus. The widespread, glaucous-stemmed, trifoliate-leaved forms of R. ursinus are vegetatively nearly identical to R. caesius. Of agricultural significance, R. ursinus is a parent of some important cultivars, including loganberry and boysenberry.
There has been uncertainty whether the name Rubus menziesii Hooker and subsequent combinations [Parmena menziesii (Hooker) Greene, R. spectabilis var. menziesii (Hooker) S. Watson, and R. ursinus var. menziesii (Hooker) Focke] pertain to R. spectabilis or R. ursinus. The protologue by Hooker describes a hairy, relatively small, procumbent plant, which is congruent with R. ursinus. The type specimen at Kew also looks like R. ursinus. In the protologue Hooker also claimed the species has red petals and suggested that it may have an affinity with R. spectabilis.
Specimens examined for this study of North American collections attributed to Rubus macrophyllus Weihe & Nees (synonym R. amplificatus Lees) are R. ursinus. If R. macrophyllus was once present in the flora area it is likely absent now; some reports of R. macrophyllus could represent hybrids. There are reports of R. ursinus hybridizing with R. bifrons and R. pensilvanicus in California (T. S. Mallah 1954; L. V. Clark and M. Jasieniuk 2012; L. A. Alice, unpubl.).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Rubus bartonianus is distinguished from the other flowering raspberries within its geographic range by its erect, unarmed stems, relatively small, simple leaves with acute to obtuse lobes, deeply cordate bases, sparsely hairy or glabrous abaxial surfaces, relatively large flowers with white petals, and densely long-hairy, clavate styles. The leaves superficially resemble those of Acer glabrum or some species of Ribes.
Rubus bartonianus is most similar to R. neomexicanus but especially R. deliciosus. The species is known only from the Snake River Canyon of Idaho and Oregon.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- 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
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