-
- © 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: 323.
- Copyright licence: Marked as being in the public domain
- Provenance: http://media.eol.org/content/2015/03/19/18/87608_orig.jpg