Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Myriophyllum heterophyllum are found here.
Table last updated 7/24/2021
† Populations may not be currently present.
References: (click for full references)
Crow, G. E. and C. B. Hellquist.
2000. Aquatic and wetland plants of Northeastern North America. Volume
1. The University of Wisconsin Press, Madison, Wisconsin.
D.H. and L.J. Mehrhoff. 1999. Introduction of nonindigenous aquatic
vascular plants in sourhtern New England: a historical perspective.
Biological Invasions. 1(2/3). pp. 281-300.
Moody, M.L. and D.H. Les. 2002. Evidence of hybridity in invasive watermilfoil (Myriophyllum) populations. Proceedings of the National Academy of Science 99(23): 14867–14871.
R.A. and J.T. Lennon. 2006. Is Hybridization Responsible for Invasive
Growth of Non-indigenous Water-milfoils? Biological Invasions 8(5):
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.