[Rosa afzeliana Fr., moreRosa andegavensis Bastard, Rosa blondaeana Déségl., Rosa borreri Woods, Rosa caesia Sm., Rosa coriifolia Fr., Rosa deseglisei Boreau, Rosa evanida (Christ) Almq., Rosa glaucophylla Winch, Rosa inconspicua Déségl., Rosa montezumae Humb. & Bonpl. ex Thory, Rosa platyphylla , Rosa sarmentacea Woods, Rosa subcanina (Christ) Crép.]
Shrub 1 - 3 m tall Stem: with arching branches and stout, flattened, recurved prickles 3 - 8 mm long. Leaves: pinnately compound, stalked, with five to seven leaflets. The leaflets are 2 - 4 cm long, egg-shaped to elliptic, toothed, and more or less hairless and glandless. Flowers: borne one to four per cluster, 4 - 5 cm across, with a usually hairless stalk and floral tube (hypanthium), a floral tube wall that thickens around a very narrow opening, non-persistent pinnately lobed and reflexed sepals, light pink to white petals 1.5 - 3 cm long, and shortly exserted styles. Fruit: bony achenes surrounded by the mature floral tube (hip). The hip is scarlet red, 1.5 - 2 cm long, and elliptic. Stipules: subtending leaves, those of main leaves linear, those of uppermost leaves enlarged to 4 mm wide.
Similar species: Rosa canina, Rosa eglanteria, and Rosa micrantha have stout, recurved prickles and small clusters of flowers with shorty exserted styles and often pinnately lobed sepals. Rosa eglanteria is distinguished by its strongly aromatic, glandular-toothed, blunt-tipped, nearly rounded to broadly elliptic leaflets that are glandular on both sides. Rosa micrantha differs by its slightly aromatic, glandular-toothed, egg-shaped to oval leaflets with pointed tips and glands beneath.
Habitat and ecology: Introduced from Europe and once grown in gardens, this species occasionally escapes cultivation into pastures and prairies.
Occurence in the Chicago region: non-native
Etymology: Rosa is the Latin name for a rose. Canina pertains to a dog.
Arching shrub 1-3 m, the stems armed with stout, flattened, hooked prickles; stipules of the principal lvs linear, those of the uppermost lvs dilated, to 4 mm wide; lfls 5 or 7, ovate-elliptic, 2-4 cm, glabrous or with a few deciduous glands on the main veins beneath; pedicels and hypanthium usually glabrous; wall of the hypanthium conspicuously thickened around the very narrow orifice; fls 1-4, long-pedicellate; sep soon reflexed, then deciduous; pet 1.5-2.5(-3) cm, pink to white; styles shortly exserted; 2n=35. Native of Europe, escaped from cult. here and there in our range.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.