Rarely escapes from cult. It is a thorny shrub to 2(-3) m, with lustrous, oblong or elliptic, finely serrate lvs 4-8 cm, and red, pink, or white fls 4-5 cm wide. (C. lagenaria)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.