Empetrum hermaphroditum Credit: Photo by Brunello Pierini

Empetrum nigrum Robert H. Mohlenbrock USDA-NRCS PLANTS Database / USDA NRCS. 1995. Northeast wetland flora: Field office guide to plant species. Northeast National Technical Center, Chester. - Not copyrighted image

Empetrum nigrum USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. Vol. 2: 479.