Erect or climbing shrubs, generally with subterranean rootstocks. Stems commonly prickly. Leaves alternate, odd-pinnate. Stipules adnate to the petiole. Flowers corymbose or solitary, red, pink or white (in our species). Calyx-tube cup-shaped or urn-shaped, constricted at the throat, becoming fleshy in fruit, 5- (rarely 4-) lobed, the lobes imbricated, spreading, deciduous or persistent. Petals 5 (rarely 4), spreading. Stamens ∞, inserted on the hollow annular disk. Carpels ∞, sessile at the bottom of the calyx; ovaries commonly pubescent; styles distinct or united. Achenes numerous, enclosed in the berry-like fruiting calyx-tube. Seed pendulous. [The ancient Latin name of the rose.]

A large genus, the number of species variously regarded, natives of the northern hemisphere. Besides the following, several others occur in the southern and western parts of North America. Type species: Rosa centifolia L.

* Styles cohering in a column; leaflets mostly 3.

1.

R. setigera.

** Styles all distinct; leaflets 5-11.

Leaves deciduous.

Calyx-lobes persistent, erect on the fruit, or spreading.

Infrastipular spines generally none.

Stems unarmed or nearly so; calyx-lobes erect on the fruit.

2.

R. blanda.

Stems armed with numerous prickles.

Leaflets 3-9, often resinous, obtuse at base; flowers solitary; calyx-lobes erect on the

fruit.

3.

R. actcularis.

Leaflets 7-11, not resinous, narrowed at base; flowers corymbed; calyx-lobes spreading.

4.

R. pratincola.

Infrastipular spines commonly present; stems prickly.

Calyx-lobes entire; native western species.

5.

R. Woodsii.

Calyx-lobes, at least the outer ones, deeply incised; introduced specie

6.

R. canina.

Calyx-lobes deciduous, spreading.

Leaflets finely serrate; spines stout, recurved.

7.

R. Carolina.

Leaflets coarsely serrate.

Infrastipular spines slender, nearly straight; native bushy species.

Stems with scattered prickles or naked; flowers often solitary.

8.

R. virginiana.

Stems very densely prickly; flowers usually solitary.

9.

R. nitida.

Infrastipular spines stout, hooked; introduced wand-like or climbing species

10.

R. rubiginosa.

Leaves evergreen; calyx-lobes persistent.

11.

R. bracteata.