Rubus ulmifolius
Rubus allegheniensis
elm-leaf blackberry
alleghaney blackberry, Alleghany blackberry, Allegheny blackberry, common blackberry, prairie rose, ronce des alléghanys, sow-teat berry
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, erect-arching, sparsely to densely hairy, sparsely to abundantly stipitate-glandular, glands usually flattened to cupulate, not pruinose;
prickles sparse to dense, erect or slightly retrorse, stout, 4–10 mm, broad-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, palmately compound, not lustrous;
stipules filiform to narrowly lanceolate, (2–)5–15(–20) mm;
leaflets (3–)5(–7), terminal ovate to lanceolate, 7–16 × 4–9 cm, base rounded to shallowly cordate, unlobed, margins finely to coarsely serrate or doubly serrate, apex acuminate to long-attenuate, abaxial surfaces with hooked prickles on midveins, moderately hairy, moderately to densely stipitate-glandular on veins.
terminal, 10–60-flowered, paniculiform or thyrsiform.
terminal on short shoots, sometimes appearing axillary, (5–)15–25-flowered, racemiform, often elongate.
unarmed or prickles moderate to dense, erect to hooked, densely short-hairy, eglandular.
unarmed or prickles sparse, hooked, densely hairy, densely short- to long-stipitate-glandular.
bisexual;
petals usually pink, sometimes white, obovate or elliptic to suborbiculate, 5–12 mm;
filaments filiform;
ovaries apically hairy.
bisexual;
petals white, obovate to elliptic, rarely suborbiculate, 8–20 mm;
filaments filiform;
ovaries glabrous or glabrate.
black, globose to ovoid, 1–1.5 cm;
drupelets 10–40, strongly coherent, separating with torus attached.
black, globose to cylindric, 1–2 cm;
drupelets 20–100, strongly coherent, separating with torus attached.
= 14.
= 14, 21, 28.
Rubus ulmifolius
Rubus allegheniensis
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 allegheniensis consists of erect-arching, usually well-armed plants, usually densely stipitate-glandular with flattened to cupulate glands, particularly about the inflorescence.
The Menominee, Meskwaki, and Potawatomi used root extracts of Rubus allegheniensis to treat eye irritation (H. H. Smith 1923, 1928, 1933). The Ojibwa used boiled extracts of the canes as a diuretic and a root extract for treating diarrhea (Smith 1932). Rubus allegheniensis is introduced in British Columbia and California, where rare and in at least California probably no more than a waif.
Rubus montanus (Porter) Porter, a name that has been used for this species, is a later homonym of R. montanus Libert ex Lejeune.
The following nothospecies names are based on putative hybrids involving Rubus allegheniensis and: R. canadensis (R. ×forestalis L. H. Bailey, R. ×immanis Ashe); R. flagellaris (R. ×boyntonii Ashe, R. ×fraternalis L. H. Bailey [based on R. ×fraternus Brainerd & Peitersen (not R. fraternus Gremli), R. ×licens L. H. Bailey, R. ×ostryifolius Rydberg); R. pensilvanicus (R. ×avipes L. H. Bailey, R. ×floricomus Blanchard, R. ×orarius Blanchard); R. setosus (R. ×abbrevians Blanchard, R. ×aculiferus Fernald, R. ×adenocaulis Fernald, R. ×angustifoliatus L. H. Bailey, R. ×ascendens Blanchard, R. ×atwoodii L. H. Bailey, R. ×clausenii L. H. Bailey, R. ×flavinanus Blanchard, R. ×frondisentis Blanchard, R. ×perspicuus L. H. Bailey, R. ×ravus L. H. Bailey).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
- Local floras:
BC, WA - Local Web sites: CalFlora, CalPhotos, Flora NW,
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
MD Biodiversity, 
MI Flora, 
MN Wildflowers, 
MO Plants, PNW Herbaria - WildflowerSearch
- iNaturalist (observations)
- USDA Plants Database
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
