Tree to 25 m; winter-buds glutinous; lfls commonly 7(9), wedge-obovate, 1-2.5 dm, abruptly acute, irregularly serrate or biserrate, pubescent beneath when young, later glabrous; infls many-fld, ovoid-conic, 2-3 dm; cal 5-7 mm; upper and lateral pet with white rotund blade marked with red or yellow at the cordate base, on slender claws; fifth petal obovate, tapering to a broad claw, or wanting; fr echinate, 5 cm thick; 2n=40. Native of se. Europe and adj. Asia, occasionally escaped from cult. in our range. May.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.