1. P. Canadénse, Benth. & Hook. (Canadian Burnet.) Stamens 4, long-exserted, club-shaped, white, as is the whole of the elongated and cylindrical spike; stem 3–6° high; leaflets numerous, ovate or oblong-lanceolate, coarsely serrate, obtuse, heart shaped at base, as if stipellate; stipules serrate.—Bogs and wet meadows, Newf. to mountains of Ga., west to Mich.
P. Sanguisórba, L. (Garden Burnet.) Stamens 12 or more in the lower flowers of the globular greenish head, with drooping capillary filaments, the upper flowers pistillate only; stems about 1° high; leaflets numerous, small, ovate, deeply cut.—Fields and rocks, N. Y. to Md. (Adv. from Eu.)
15. RÒSA, Tourn. Rose.
Calyx-tube urn-shaped, contracted at the mouth, becoming fleshy in fruit. Petals 5, obovate or obcordate, inserted with the many stamens into the edge of the hollow thin disk that lines the calyx-tube and within bears the numerous pistils below. Ovaries hairy, becoming bony achenes in fruit.—Shrubby and usually spiny or prickly, with odd-pinnate leaves, and stipules cohering with the petiole; stalks, foliage, etc., often bearing aromatic glands. Many of the species are very variable in their characters, and are often indeterminable upon imperfect specimens. (The ancient Latin name.)
[*] Styles cohering in a protruding column, as long as the stamens.
1. R. setígera, Michx. (Climbing or Prairie Rose.) Stems climbing, armed with stout nearly straight scattered prickles, not bristly; leaflets 3–5, ovate, acute, sharply serrate, smooth or downy beneath; stalks and calyx glandular; flowers corymbed; sepals pointed; petals deep rose-color changing to white; fruit (hip) globular.—Borders of prairies and thickets, Ont. to Ohio, S. C., and Fla., west to Wisc., Neb., and Tex.; also cultivated. July.—The only American climbing rose, or with united protruding styles; strong shoots growing 10–20° in a season.
[*][*] Styles distinct; sepals connivent after flowering and persistent; pedicels and receptacles naked.
[+] Fruit oblong-obovate to oblong; infrastipular spines usually none.
2. R. Engelmánni, Watson. Stems usually 3–4° high or less; infrastipular spines, when present, straight and slender; prickles often abundant; leaflets 5–7, often somewhat resinous-puberulent beneath and the teeth serrulate; flowers solitary; sepals entire, naked or hispid; fruit 6–12´´ long.—Whisky Island, L. Huron, shores of L. Superior, and west to the Red River valley, and in the mountains from N. Mont, and N. Idaho to Col.
[+][+] Fruit globose; infrastipular spines none; acicular prickles often present.