- Black Haw Bark Tea (25 tea bags, ZIN: 518776): The bitter-tasting stem and root bark of black haw, also called sloe or stagbush, can support the liver and nervous system. It contains coumarins, scopoloteine, amentoflavone, arbutin, oleanolic and ursolic acids, salicin, and tannin which are responsible for the herb's ability to act as an antispasmodic, a uterine tonic, a nervine, and an anti-dysentery. Black haw may have been used traditionally to help support menstrual pains, supporting menopau