Rosa setigera Michx.

A rambling shrub making slender stems several yards long in a season, armed with short, hooked prickles, not downy. Leaves trifoliolate, with a downy, glandular stalk and narrow stipules edged with glands. Leaflets among the largest in the genus, up to 3 in. long by over 2 in. wide, ovate, coarsely toothed, deep green and glabrous above, pale and downy beneath. Flowers 2 to 21⁄2 in. across, variable in colour from nearly white to crimson, several in corymbs; the stalk glandular. Sepals ovate, pointed, 1⁄2 in. long, very downy. Fruits globose, about 1⁄3 in. in diameter, with the sepals fallen away.

Native of E. and Central North America, from Ontario to Florida, and west to Kansas and Texas. Introduced in 1800. This is the most distinct and, in its flowers, perhaps the most beautiful of N. American roses. It is the only one from that region belonging to the group whose styles are united in a column (Synstylae); the only one with normally three leaflets, and the only climbing species. It is an attractive plant, producing its large, rich rosy blossoms in clusters 6 in. or more across, but they have little or no fragrance. Flowering in July and August when few wild roses or shrubs of any kind are in flower, its value is increased. It may be trained up rough branches of oak, then left to form a tangle.

Many hybrids have been raised from R. setigera in the USA. Of these the oldest were bred by Samuel Feast of Baltimore, Maryland, who made a sowing of the prairie rose in 1836 and crossed it with Hybrid Perpetuals, Noisettes, etc. Some of the offspring, put into commerce in 1843, are still cultivated, e.g., ‘Baltimore Belle’ and ‘Queen of the Prairies’.