Viburnum prunifolium (known as blackhaw or black haw, blackhaw viburnum, sweet haw, and stag bush) is a species of Viburnum native to northeastern North America, from Connecticut west to eastern Kansas, and south to Alabama and Texas.
It is a deciduous shrub or small tree growing to 2–9 m tall with a short crooked trunk and stout spreading branches. The bark is reddish-brown, very rough on old stems. The branchlets are red at first, then green, finally dark brown tinged with red.
It has both value in the pleasure garden, providing good fall color and early winter provender for birds, and medicinal properties.
- Medicinal uses - 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.
The primary use of black haw today is to prevent menstrual cramps. The salicin in black haw may also be of use in pain relief.
Black haw's primary use was to prevent miscarriages.
- Safety issues - Like many other plants, including many food plants and those used as culinary herbs, black haw contains salicin, a chemical relative of aspirin. Those who are allergic to that substance should not use black haw.
The chemicals in black haw do relax the uterus and therefore probably prevent miscarriage; however, the salicin may be teratogenic. Consequently, pregnant women should not use black haw in the first two trimesters.