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elm-leaf blackberry

stone bramble

Habit Shrubs, 30–50 dm, unarmed or armed. Herbs or subshrubs, to 4 dm, armed or unarmed.
Stems

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.

usually creeping, ± woody basally, sparsely to densely hairy, eglandular, not pruinose;

prickles absent or sparse, erect, weak, 1–3 mm, narrow-based.

Leaves

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 free from petioles, lanceolate to ovate or elliptic, 6–11 mm;

petiole 2–11 cm;

petiolule of terminal leaflet 8–20 mm;

lateral leaflet sessile or subsessile;

terminal leaflets ovate to elliptic, 4–8 × 3–7 cm, base tapered, unlobed, lateral leaflets sometimes shallowly lobed, margins coarsely doubly serrate, apex acute, abaxial surfaces unarmed, sparsely hairy, eglandular.

Inflorescences

terminal, 10–60-flowered, paniculiform or thyrsiform.

axillary, 1–6-flowered, cymiform or umbelliform.

Pedicels

unarmed or prickles moderate to dense, erect to hooked, densely short-hairy, eglandular.

unarmed or prickles weak, erect, hairy, eglandular or sparsely stipitate-glandular.

Flowers

bisexual;

petals usually pink, sometimes white, obovate or elliptic to suborbiculate, 5–12 mm;

filaments filiform;

ovaries apically hairy.

bisexual;

petals greenish white, narrowly obovate, 5.5–7 mm;

filaments laminar;

ovaries glabrous.

Fruits

black, globose to ovoid, 1–1.5 cm;

drupelets 10–40, strongly coherent, separating with torus attached.

red, globose, 0.5–1.5 cm;

drupelets 1–10, not or weakly coherent, separating with torus attached.

2n

= 14.

= 28.

Rubus ulmifolius

Rubus saxatilis

Phenology Flowering May–Jul. Flowering May–Jul.
Habitat Woodland edges, open areas, disturbed areas, moist soil Birch scrub, talus slopes
Elevation 0–500 m (0–1600 ft) 1300–2100 m (4300–6900 ft)
Distribution
from FNA
CA; NJ; NV; OR; WA; s Europe; c Europe; n Africa [Introduced in North America; introduced also in s South America]
[WildflowerSearch map]
[BONAP county map]
from USDA
Greenland; Eurasia
[BONAP county map]
Discussion

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 saxatilis is defined by its creeping, unarmed or weakly armed stems, ternate leaves, and relatively small white petals. It has very weak prickles that detach easily, sometimes giving plants an unarmed appearance. The species is known in the flora area from only two sites in southern Greenland (T. W. Böcher 1938; D. B. Jensen and K. D. Christensen 2003).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 9, p. 54. FNA vol. 9, p. 52.
Parent taxa Rosaceae > subfam. Rosoideae > tribe Rubeae > Rubus Rosaceae > subfam. Rosoideae > tribe Rubeae > Rubus
Sibling taxa
R. allegheniensis, R. arcticus, R. bartonianus, R. bifrons, R. caesius, R. canadensis, R. chamaemorus, R. cuneifolius, R. deliciosus, R. flagellaris, R. glaucifolius, R. hispidus, R. idaeus, R. illecebrosus, R. laciniatus, R. lasiococcus, R. leucodermis, R. neomexicanus, R. nivalis, R. niveus, R. nutkanus, R. occidentalis, R. odoratus, R. parviflorus, R. parvifolius, R. pascuus, R. pedatus, R. pensilvanicus, R. phoenicolasius, R. pubescens, R. repens, R. saxatilis, R. setosus, R. spectabilis, R. trivialis, R. ursinus, R. vestitus
R. allegheniensis, R. arcticus, R. bartonianus, R. bifrons, R. caesius, R. canadensis, R. chamaemorus, R. cuneifolius, R. deliciosus, R. flagellaris, R. glaucifolius, R. hispidus, R. idaeus, R. illecebrosus, R. laciniatus, R. lasiococcus, R. leucodermis, R. neomexicanus, R. nivalis, R. niveus, R. nutkanus, R. occidentalis, R. odoratus, R. parviflorus, R. parvifolius, R. pascuus, R. pedatus, R. pensilvanicus, R. phoenicolasius, R. pubescens, R. repens, R. setosus, R. spectabilis, R. trivialis, R. ulmifolius, R. ursinus, R. vestitus
Synonyms R. discolor, R. ulmifolius var. anoplothyrsus
Name authority Schott: Isis (Oken) 1818: 821. (1818) Linnaeus: Sp. Pl. 1: 494. (1753)
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