Rubus nivalis |
Rubus bifrons |
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dwarf snow bramble, snow bramble, snow dewberry, snow dwarf bramble, snow raspberry |
European blackberry, Himalayan berry, Himalayan blackberry, twice-leaf blackberry |
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Habit | Shrubs, to 1.5 dm, armed. | Shrubs, (3–)10–50 dm, armed. |
Stems | perennial, creeping, sparsely hairy, glabrescent, eglandular, not pruinose; prickles sparse, strongly retrorse, stout, to 1 mm, broad-based. |
biennial, arching, sometimes creeping early or with age, sparsely to densely hairy, eglandular or sparsely sessile-glandular, not or weakly pruinose; prickles moderately dense, hooked, retrorse, or erect, stout, 4–10 mm, broad- or narrow-based. |
Leaves | evergreen, simple or ternate; stipules adnate to petioles, broadly elliptic to ovate, (6–)8–10 mm; blade ovate to cordate, (2.5–)3–5(–8) cm, lobe or leaflet base cordate, shallowly 3-lobed, margins coarsely, singly or doubly dentate, apex acute to obtuse, abaxial surfaces with prickles along midveins, glabrous or sparsely hairy, eglandular, both surfaces lustrous fresh. |
deciduous to semievergreen, palmately compound; stipules filiform to linear, 7–15 mm; leaflets 3–5, terminal elliptic or ovate to suborbiculate, 6–15 × 4–9 cm, base rounded to shallowly cordate, unlobed, margins moderately to coarsely serrate, apex acute or acuminate to short-attenuate, abaxial surfaces white (gray-green in shade), with hooked prickles on largest veins, short-velutinous to tomentose, eglandular, rarely sparsely sessile-glandular along midveins. |
Inflorescences | 1–2-flowered. |
terminal, sometimes also axillary, 10–60(–100)-flowered, thyrsiform, projected well beyond subtending leaves. |
Pedicels | prickles scattered, retrorse, moderately to densely hairy, eglandular. |
prickles moderate to dense, hooked to retrorse or erect, densely hairy, eglandular or sparsely to moderately sessile-glandular. |
Flowers | bisexual; petals magenta to pink, elliptic to oblanceolate or spatulate, (5–)8–10 mm; filaments filiform; ovaries moderately hairy, styles glabrous. |
bisexual; petals white to pink, obovate or elliptic to orbiculate, 10–15 mm; filaments filiform; ovaries apically hairy. |
Fruits | red, hemispheric, 0.4–1 cm; drupelets 3–10, not coherent, separating from torus. |
black, globose to subcylindric, 1–2 cm; drupelets 15–40(–50), strongly coherent, separating with torus attached. |
2n | = 14. |
= 28, 48. |
Rubus nivalis |
Rubus bifrons |
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Phenology | Flowering Jun–Sep. | Flowering (Apr–)May–Aug(–Sep). |
Habitat | Moist, semishaded forests, glades, moist soil, logged areas | Woodland edges, dry or mixed woods, open areas, often disturbed, roadsides, moist soil |
Elevation | 0–1700 m (0–5600 ft) | 0–1200(–1800) m (0–3900(–5900) ft) |
Distribution |
CA; ID; OR; WA; BC
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AK; AL; AR; AZ; CA; CO; CT; DC; GA; ID; IL; KS; KY; LA; MA; MD; MO; MS; MT; NC; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; TN; TX; UT; VA; WA; BC; ON; Europe [Introduced in North America]
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Discussion | Rubus nivalis is recognized by its creeping, prickly stems, simple to ternate, evergreen leaves, broadly elliptic to ovate stipules, two leaflets, relatively small flowers, and magenta to pink petals. Its closest relative is likely the Mexican R. pumilus Focke. Asian species previously classified in subg. Chamaebatus (Focke) Focke are hexaploid (M. M. Thompson 1997) and not phylogenetically close; R. nivalis appears to be sister to all blackberries of subg. Rubus (L. A. Alice and C. S. Campbell 1999; Alice et al. 2008). The fruits of Rubus nivalis are eaten fresh, stewed, and canned by the Hoh and Quileute Indians (A. B. Reagan 1936). The only known specimen of Rubus nivalis from California was collected in 1961 from Del Norte County at 1250 m near the Oregon border. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Rubus bifrons lacks the strongly pruinose stems of the related R. ulmifolius and has usually much larger leaves. The species also often has much broader inflorescences than R. ulmifolius or the related R. vestitus. It is less densely glandular and has longer and more open inflorescences than R. pascuus, and unlike the latter it has spreading, not erect, primocane leaves. Rubus bifrons also lacks the stipitate-glandular hairs and nearly round primocane terminal leaflets of R. vestitus; seedlings of R. bifrons can be densely stipitate-glandular. L. H. Bailey (1941–1945), M. L. Fernald (1950), Y. Heslop-Harrison (1968), and H. A. Gleason and A. Cronquist (1991) distinguished between Rubus bifrons and another species (referred to as either R. discolor or R. procerus P. J. Müller ex Boulay, both often considered synonyms of R. armeniacus), based on stem shape and indument, prickle shape and angle, leaf shape and margins, inflorescence shape, and petal color. Plants in North America identified as either R. bifrons or the other species can vary broadly in any of these characters, even within individual stems, making it extremely difficult or impossible to distinguish between these species in the flora area. Recent research addressing the genetics or species distinctiveness in this complex in Europe (J. Kollmann et al. 2000) and Australia (K. J. Evans et al. 2007) did not sample plants from North America, and recent work within the flora area (L. V. Clark et al. 2013) addressed this complex only in California, Oregon, and Washington. Until a much-needed genetic study is performed that includes a broad selection of plants of ser. Discolores from throughout North America, Europe, and elsewhere, the precise identities of all of our material in this complex will be elusive. With this degree of uncertainty, a conservative approach is taken here, which is consistent with the treatment herein of the native blackberries. The results of more comprehensive DNA research may show that a different name than R. bifrons is to be used in the flora area. The name R. discolor often has been misattributed as a synonym of R. armeniacus; it is a synonym of R. ulmifolius (H. E. Weber 1985). In the flora area, Rubus bifrons is most abundant from northern California northward to British Columbia, where it can grow in great density over large areas, often to the exclusion of all other vegetation (for example, K. Williams et al. 2006). There are reports of R. bifrons (as R. armeniacus or R. procerus) hybridizing with R. ursinus (T. S. Mallah 1954; L. V. Clark and M. Jasieniuk 2012; B. Sutherland and L. Alice, unpubl.) and R. laciniatus (R. K. Bammi and H. P. Olmo 1966). Rubus thyrsoideus Wimmer is an illegitimate name that applies here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 45. | FNA vol. 9, p. 36. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Rubeae > Rubus | Rosaceae > subfam. Rosoideae > tribe Rubeae > Rubus |
Sibling taxa | ||
Synonyms | R. armeniacus, R. linkianus | |
Name authority | Douglas: in W. J. Hooker, Fl. Bor.-Amer. 1: 181. (1832) | Vest: Steyermärk. Z. 3: 163. (1821) |
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