Rare Species Guide

  Basis for Former Listing

Potamogeton vaseyi (Vasey's pondweed) is an aquatic macrophyte that inhabits small soft water lakes in the northeastern portion of North America. It is reported to be an uncommon species across its range (Haynes and Hellquist 2000), but it seems to be especially uncommon in Minnesota, where it reaches the very western edge of its range. Several threats to the species' habitat have been identified, including declining water quality, which seems to be a statewide trend, and the accelerating invasion of non-native species, which seems to be a worldwide trend. Potamogeton vaseyi was listed as a special concern species in Minnesota in 1984.

  Basis for Delisting

Recent aquatic plant surveys by the Minnesota Biological Survey discovered P. vaseyi in just over 120 lakes of more than 2,000 lakes that were surveyed. It is now known to be more common and widespread than once thought to be. Special concern status is no longer necessary, and Potamogeton vaseyi was delisted in 2013.

  References and Additional Information

Adams, J. W. 1929. Potamogeton vaseyi in southwestern Pennsylvania. Bartonia 10:28-29.

Fernald, M. L. 1932. The linear-leaved North American species of Potamogeton section Axillares in Memoirs of the Gray Herbarium of Harvard University 3:1-183.

Haynes, R. R., and C. B. Hellquist. 2000. Potamogeton. Pages 48-70 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 22. Oxford University Press, New York, New York.

Hellquist, C. B. 1977. Observations on some uncommon vascular aquatic plants in New England. Rhodora 79:445-452.

Pip, E. 1987. The ecology of Potamogeton species in central North America. Hydrobiologia 153:203-216.

Minnesota Department of Natural Resources. 2012. Statement of need and reasonableness. Division of Ecological and Water Resources, Minnesota Department of Natural Resources, St. Paul. 337 pp.