database: Lycopodiopsida of North America Update; Updated for ITIS by the Flora of North America Expertise Network, in connection with an update for USDA PLANTS (2007-2010)
database: NODC Taxonomic Code;
database: The PLANTS Database; National Plant Data Center, NRCS, USDA. Baton Rouge, LA 70874-4490 USA. http://plants.usda.gov
database: The PLANTS Database; National Plant Data Center, NRCS, USDA. Baton Rouge, LA 70874-4490 USA. http://plants.usda.gov
Christenhusz, Maarten J. M., Xian-Chun Zhang, and Harald Schneider 2011-02-18. Phytotaxa, vol. 19. . . 7-54. . Available online at http://www.mapress.com/phytotaxa/content/2011/f/pt00019p054.pdf.
