Coefficient of Conservatism:
Coefficient of Wetness:
M. R. Penskar
Sandy shores and open, sandy meadows, in sites with fluctuating water levels.
Collected at White Pigeon, St. Joseph Co., August 11, 1837, during the first Geological Survey of Michigan, and not discovered again until found in Allegan Co. in 1989. North American plants are sometimes recognized as var. parvulus (Engelm.) Fassett and occur along the Gulf and Atlantic coasts, with very few inland stations.
Lehtonen (2009) presents evidence that Echinodorus is polyphyletic and our plant should be placed into the small genus Helanthium as H. tenellum (Mart.) Britton.