A vigorous, deciduous shrub, with stout, erect, very pale brown stems up to 8 ft high, bark peeling; young stems covered with glandular hairs. Leaves simple, amongst the largest of hardy Rubi, five-lobed, vine-like, 4 to 10 (or even 12) in. across; lobes pointed, sharply and irregularly toothed, hairy on both sides, but especially beneath, soft and velvety to the touch. Flowers fragrant, bright purple, 11⁄2 to 2 in. across, borne in large, branching, corymbose clusters at the ends of the shoots; the stalks conspicuously furnished with dense glandular hairs, the calyx similarly covered, each of its five divisions narrowed to a tail-like point. Fruits flat and broad, red when ripe, but rarely seen in this country. Bot. Mag., t. 323.
Native of eastern N. America introduced in 1770. Next to R. deliciosus, this is perhaps the most ornamental of Rubi, in regard to blossom. It flowers from July to September, and few shrubs at that time equal it in beauty and fragrance. It loves a semi-shaded spot, where its flowers are protected from the fierce midday and early afternoon sun; in such a place the blossoms last longer. It is a rampant grower, and soon forms a thicket; good soil should be provided and the plants are all the better if pulled apart every few years, and planted more thinly. The old stems should be removed every winter. It is very similar in growth to R. parviflorus (q.v.), but starts to flower a month later.
R. × fraseri Rehd. R. robustus Fraser, not Presl. – A hybrid between R. odoratus and R. parviflorus (seed-parent) raised in 1918 by George Fraser, Ucluelet, British Columbia. Described by Fraser as a vigorous, compact shrub to 8 ft high, resembling R. odoratus in its non-suckering habit but with acuminately lobed leaves inherited from the seed-parent. Flowers rosy at first, becoming pale purple.