200405 Feverwort, Late Horse Gentian, Wild Coffee (Triosteum perfoliatum) - USDA Illustration

Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 3

USDA, NRCS. 2019. The PLANTS Database (http://plants.usda.gov). National Plant Data Team, Greensboro, NC 27401-4901 USA.

click here for Per's Wild Flower home Page