Viburnum prunifolium (Blackhaw, also spelled Black haw, Blackhaw Viburnum, or Stag Bush), is a species of Viburnum native to southeastern North America, from Connecticut west to eastern Kansas, and south to Alabama and Texas.
For centuries, black haw has been used for medical purposes, mainly for gynecological conditions. The bark is the part of the plant used in treatments. The active components include scopoletin, aesculetin, salicin, 1-methyl-2,3 clibutyl hemimellitate, and viburnin. Tannin is another chemical component of black haw. Native Americans used a decoction of black haw to treat gynecological conditions, including menstrual cramps, aiding recovery after childbirth, and in treating the effects of menopause. As a folk remedy, black haw has been used to treat menstrual pain, and morning sickness. Due to its antispasmodic properties, the plant may also be of use in treating cramps of the digestive tract or the bile ducts