200409 Helleborine (Epipactis
helleborine) - USDA Illustration
%20-%20USDA%20Illustration.JPG)
USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. Illustrated flora
of the northern states and Canada. Vol. 1
USDA, NRCS. 2023. The PLANTS Database (http://plants.usda.gov). National Plant Data Team, Greensboro, NC 27401-4901 USA.