Rugosa rose, or Japanese rose, is an introduced ornamental species native to coastal regions of eastern Asia (northeastern China, Japan, Korea and southeastern Siberia). It is invasive and naturalized in many European countries where it grows on sandy/gravelly beaches and dune grassland communities Weidema (2006). In North America, it is reported from several north/ northeastern US states (CT, DE, IL, MA, MD, ME, MI, MN, MO, NH, NJ, NY, OH, PA, RI, VA, VT, WI, WV) as well as Alaska and Washington; it is also reported from Canada (NB, NF, NS, ON, PE, QC and British Columbia) (USDA 2010). In British Columbia, it has been collected from two locations: Vancouver (UBC area) and Martin's Island, where it was collected in 1987. However, it is widely grown in gardens.
Rugosa rose is a small prickly shrub rose with white to dark pink flowers. Weidema (2006) describes it as follows: "The surface of the leaves is wrinkled, dark green, smooth above while pubescent and slightly sticky underneath. The twigs are stout and covered with thin, straight sharp spines of various sizes. The flowers are big (8-10 cm across) and can be white or light to dark pink depending on the cultivar, also doubled flowers occur in the wild. The fruits are large and slightly flattened, shiny, deep red and fleshy "rose-hips" which ripen in late summer." Dispersal is both via seeds (bird dispersed) and by vegetative reproduction (rhizomes). Weidema (2006) reports long distance dispersal: hips are buoyant and can float for weeks in fresh and salt water. This species is not yet widespread in BC. However, in Europe it has exhibited a lag phase before spreading invasively in coastal dunes (Weidema 2006). Thick growth through vegetative reproduction impacts native species through displacement and shading, and affects dune processes where it has invaded (Weidema 2006). As a preventative measure, this species should not be planted near coastal dunes. |
Synonyms and Alternate Names:
Rosa rugosa var. albiflora Koidz.
KEY TO ROSA
1. Stipules deeply fringed or comb-like; inflorescence multiflowered..........R. multiflora 1a. Prickles strongly curved, stout; calyx-lobes often with conspicuous lateral segments and usually reflexed after flowering.
2. Lower surface of leaflets stalked-glandular..............R. eglanteria 1a. Prickles not or slightly curved, often slender; calyx-lobes usually without lateral segments, usually ascending or erect after flowering.
3. Calyx-lobes deciduous in fruit, 12 mm long or less; petals 15 mm long or less...............R. gymnocarpa 4. Stems with well-defined infrastipular prickles (pair of prickles at or just below each node) or nearly unarmed.
5. Calyx-lobes usually glandular-bristly; leaflets finely toothed; plants from west of the Coast-Cascade Mountains............R. pisocarpa
6. Flowers small and clustered; calyx-lobes mostly 1-2 cm long and 2-3.5 mm wide at base; petals 1.2-2.5 cm long................R. woodsii 4. Stems more or less bristly with slender prickles; infrastipular prickles, if any, like the others.
7. Flowers mostly solitary, usually on lateral branchlets of current season; leaflets usually 5 to 7 (9); petals more than 2 cm long..................R. acicularis Source: Illustrated Flora of British Columbia (Vol. 4). (1999) |