Also known as
Viburnum opulus, Guelder rose, Black Haw, Cranberry Tree, Dog Rowan Tree, Viburnum, May Elder, King’s Crown, and May Rose.
Cramp bark is a large deciduous shrub growing as much as 15 feet (5 m) tall and 15 feet wide. It is native to the moist lowland forests of England and Scotland and naturalized to moist forests of the northern United States and southern Canada. The bark is stripped before the leaves change color in the fall, or before the buds open in the spring. A member of the honeysuckle family, cramp bark bears large white flowers, up to 5 inches (12 cm) across that yield red berries in the fall. The berries are eaten like cranberries, although moderation is recommended. Historically, the berries, once dried, have been used for making ink.
Coumarins, scopoletin, tannin.
Dried bark, harvested in the autumn before leaves change color, or in the spring before leaves open. The leaves and fruit are used in laxatives.
Teas or tinctures. In rare instances, used as a ground herb administered in capsules. Often combined with corydalis and/or valerian for pain.
Cramp bark is essentially nontoxic, although taking large quantities of the fruit or leaf can cause diarrhea. Some reports have shown that people with sensitivity to aspirin may also have a sensitivity to cramp bark, so caution should be exercised.
For educational purposes only This information has not been evaluated by the Food and Drug Administration.
This information is not intended to diagnose, treat, cure, or prevent any disease.