Wind, P. (2019), "Karplanter", i Moeslund, J.E. m.fl. (red.), Den danske Rødliste 2019, Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, hentet 31. juli 2021
"Connecticut's Endangered, Threatened and Special Concern Species 2015". State of Connecticut Department of Energy and Environmental Protection Bureau of Natural Resources. Retrieved 18 January 2018. (Note: This list is newer than the one used by plants.usda.gov and is more up-to-date.)
