Much like R. allegheniensis; primocane lfls mostly 3, or 5 with the intermediate pair subsessile or poorly developed; terminal lfl of primocane lvs 8-15 cm, broadly ovate to subrotund, at least three-fourths as wide as long, commonly short-acuminate or abruptly acuminate; sharply or coarsely or irregularly serrate, broadly rounded to subcordate at base; infl racemiform, but not so long and many-fld as in no. 17 [Rubus allegheniensis Porter]. Que. to Wis., s. to Md., W.Va., and Mo. Perhaps actually a series of hybrids of R. allegheniensis with R. pensilvanicus and/or other spp. The name R. orarius may not properly apply, but is here retained for historical continuity with Gleason's treatment while we await a proper biosystematic study of the group.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.