Eyre, F. H., ed. Forest cover types of the United States and Canada. Society of American Foresters. Folkerts, George W. 1977. Endangered and threatened carnivorous plants of North America.
Extinction is forever.
Folkerts, George W. 1982. The Gulf Coast pitcher plant bogs. Vegetation and environmental features of forest and range ecosystems. Jones, F. M. 1921. Pitcher plants and their moths.