Rubus occidentalis is a species of Rubus native to eastern North America. Its common name black raspberry is shared with the closely related western American species Rubus leucodermis. Other names occasionally used include wild black raspberry, black caps, black cap raspberry, thimbleberry, and scotch cap. Black raspberries are high in anthocyanins. This has led to their being very useful as natural dyes. Preliminary studies to evaluate their benefit for cancer treatment in mammalian test systems are ongoing and a small-scale clinical trial has begun on patients with Barrett's esophagus.