Alder Buckthorn is a European shrub native to Asia and Europe that is now distributed throughout North America. It is also known as Black Dogwood because the wood was once used to produce fine charcoal. The wood was also popular with German gunpowder makers, who dubbed the small tree Pulverholz, which means Powder Wood. 

What is buckthorn bark used for? Buckthorn bark is used to make a natural yellow dye, which becomes inky black with the addition of iron as a mordant. Prior to use in teas or tisanes, buckthorn bark must be aged for one year. While buckthorn bark has a slightly bitter but not unpleasant taste, moderation is advised because it contains the phenolic compound emodin.