Deciduous shrubs, mostly prickly, erect, climbing or scrambling. Shoots moderate, rounded; pith relatively large, brown, rounded. Buds small, solitary, sessile, ovoid, with 3 or 4 visible scales. Leaf-scars alternate, narrow, straight or slightly curved; bundle-traces 3; stipule-scars none. Fruit a berry-like fleshy receptacle (hip) enclosing numerous achenes; the sepals, crowning the summit, are quickly deciduous or persistent into winter.
Members of this genus are so variable, as a result of extensive cultivation, that the following key should be regarded as highly tentative.
a. Stems climbing, leaning or trailing
b. Plants of dry clearings or roadsides
c. Native species
c. Introduced cultivated plant
b. Plant of swamp thickets
Stems bushy, erect
b. Canes densely bristly and acicular-prickly
b. Canes usually prickly but not densely bristly
c. Stems short, not averaging over 0.5 m. tall
d. Prickles straight, slender
d. Prickles thick, more or less curved
c. Stems taller, 1-2 m. high or more
d. Sepals deciduous from the fruit
d. Sepals tardily deciduous, persisting into the winter
1. R. setigera Michx. Prairie Rose. Stems more or less climbing, to 5 m. long, not bristly but armed with thick, nearly straight, scattered prickles; fruit globose, 8-10 mm. in diameter, glandular, the sepals deciduous. Thickets, Florida to Texas, north to New York, Indiana, and Kansas (Fig. 149).
2. R. multiflora Thunb. Multiflora Rose. Rambler Rose. Trailing or arching, with long reclining or climbing branches; prickles hooked. Introduced from Asia, escaped from cultivation and naturalized (Fig. 150).
Fig. 149. Rosa setigera.
Fig. 150. Rosa multiflora.
Fig. 151. Rosa eglanteria.
3. R. eglanteria L. Sweetbrier. Eglantine. Stems slender, 1-2 m. high, or forming longer wands, armed with strong hooked prickles, sometimes with scattered smaller ones; sepals tardily deciduous from the scarlet or orange hip. Introduced from Europe, escaped from cultivation and naturalized (Fig. 151).
4. R. canina L. Dog Rose. Stem 3 m. high or less, coarse, with large recurved prickles; sepals promptly falling from the ellipsoid scarlet hip. Introduced from Europe, escaped from cultivation and naturalized (Fig. 152).
5. R.. virginiana Mill. Pasture Rose. Stems erect, often tall and thick, 2-20 dm. high, with large usually curved prickles; sepals soon deciduous from the red fruit. Thickets, Newfoundland to Ontario, south to Alabama and Missouri (Fig. 153).
6. R. palustris Marsh. Swamp Rose (R. Carolina L.). Stems usually tall, climbing or scrambling, 3-25 dm. high, with thick straight or curved prickles; fruit globose or depressed-globose, about 8 mm. high, glandular-hispid; sepals deciduous from the depressed-globose or ellipsoid fruit. Swamps and wet thickets, New Brunswick to Ontario and Minnesota, south to Florida and Arkansas (Fig. 154).
7. R. Carolina L. Low Pasture Rose. (R. serrulata of authors, not Raf.). Stems erect, 3-9 dm. high; prickles needlelike, straight; sepals deciduous from the fruit. Dry soil, Florida to Texas, north to Nova Scotia, Minnesota, and Nebraska (Fig. 155).
Fig. 146. Rubus occidentalis.
Fig. 147. Rubus hispidus.
Fig. 148. Rubus allegheniensis.
8. R. acicularis Lindl. Northern Rose. Canes 3-12 dm. high, densely bristly and acicular-prickly; sepals persisting and erect in fruit. Rocky slopes, Quebec to Yukon, south to Colorado, South Dakota, Michigan, and West Virginia.