An east-Asian sp. with cymes mostly 7-rayed and pedunculate on short lateral branches, and with mostly smaller (6-10 cm) lvs and blue-black fr, sometimes escapes from cult. (V. tomentosum) The Japanese snowball is a form with all fls sterile.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.