Primocanes ascending, soon arched and rooting at the tip, sparsely beset with stout hooked prickles with expanded base, not bristly, glaucous when young, primocane lvs 3-foliolate, the lfls broadly ovate, subcordate at base, softly pubescent beneath; infl subpaniculiform, some of its axillary branches with 2 or more fls. Native of Eurasia, occasionally escaped from cult.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.