Cramp bark (Viburnum opulus) also known as guelder rose, highbush cranberry, & snowball tree is a tall, flowering shrub with red berries & clusters of white flowers. Native to Europe, it also grows well in the United States & Canada. This herb has traditionally been used to help with pain from muscle cramps, especially period cramps, although other parts of the plant may also offer benefits. Besides shows promising potential to relieve pain & promote healthy kidney function, & emerging research suggests that it may offer many other benefits as well. Please be aware that you are using all our herbal products on your own responsibility. If you are unsure about any species of herbs, you should first contact with your General Practicioner for more advice. Guelder Rose Bark/Herbal Tea Dried Herb Herbs For Cramp Bark Viburnum Opulus