Rubus ulmifolius
Rubus glaucifolius
elm-leaf blackberry
Cuyamaca raspberry, San Diego raspberry, wax leaf raspberry
biennial, erect, then arching, usually moderately, rarely sparsely, hairy hairs stellate, eglandular, strongly pruinose;
prickles absent or sparse to dense, erect to hooked, stout, 3–10 mm, broad-based.
biennial, creeping, glabrous, eglandular, strongly pruinose;
prickles sparse, erect or slightly curved, weak, slender, 2–3 mm, narrow-based.
persistent or nearly so, ternate to palmately compound;
stipules filiform to linear, 4–12 mm;
leaflets 3–5, terminal ovate, elliptic, or suborbiculate to obovate, 4–10 × 2–6(–9) cm, base rounded to cuneate, unlobed, margins finely to moderately serrate, apex acute or acuminate to attenuate, abaxial surfaces with hooked prickles on larger veins, densely white short-velutinous, hairs usually minute, eglandular.
deciduous, ternate;
stipules filiform to linear, 3–10 mm;
terminal leaflets ovate to elliptic, 4–8 × 3–7 cm, base tapered or subcordate, often 2-lobed, margins coarsely dentate, apex acute to rounded, abaxial surfaces unarmed, densely white-tomentose, eglandular.
terminal, 10–60-flowered, paniculiform or thyrsiform.
terminal and axillary, (1–)2–4(–10)-flowered, cymiform.
unarmed or prickles moderate to dense, erect to hooked, densely short-hairy, eglandular.
unarmed, finely hairy, stipitate-glandular.
bisexual;
petals usually pink, sometimes white, obovate or elliptic to suborbiculate, 5–12 mm;
filaments filiform;
ovaries apically hairy.
bisexual;
petals white, oblong to oblanceolate, 4–8 mm;
filaments laminar;
ovaries white-tomentose.
black, globose to ovoid, 1–1.5 cm;
drupelets 10–40, strongly coherent, separating with torus attached.
reddish purple, hemispheric to conic, 0.4–1 cm diam.;
drupelets 10–40, coherent, separating from torus.
= 14.
Rubus ulmifolius
Rubus glaucifolius
Rubus ulmifolius can be distinguished, especially from the closely related R. bifrons and R. vestitus, by its strongly pruinose stems, finely serrate leaflets, and lack of glands throughout. Unlike R. ulmifolius, strongly pruinose native Rubus species lack relatively large and showy pink petals. Some new stems developing from tip-rooting, and early leaves on such stems (especially in shade), are not whitened abaxially and are tomentose. Such unusual stems develop typical leaves and surfaces in parts formed later.
There has been nomenclatural confusion over unarmed plants of Rubus ulmifolius (see E. Monasterio-Huelin and H. E. Weber 1996). Rubus inermis Willdenow is an illegitimate later homonym of R. inermis Pourret, and the type specimens for both names are of poor-quality. If an unarmed variety of R. ulmifolius is to be recognized, such as occurs in California, the name var. anoplothyrsus Sudre should be used instead of var. inermis (Willdenow) Focke.
Rubus ulmifolius is attractive and is potentially weedy but relatively uncommon, found primarily in coastal California from the San Francisco Bay region southward. It probably no longer persists in New Jersey, last collected there in 1897, and it is rare in Nevada and Oregon. Rubus ulmifolius likely hybridizes with R. bifrons where they co-occur; it is one of relatively few diploid and sexually reproducing species of European blackberries.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Rubus glaucifolius is found in the Sierra Nevada and Klamath mountains as well as the Peninsular and northern Coastal ranges in California, and in adjacent Oregon only in Jackson County.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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