branched bur-reed

Sparganium erectum is a member of the genus Sparganium and is recognized by its branched structure. It is native to multiple regions, including the conterminous 48 United States, Belgium, and parts of Europe and Asia. The species has been the subject of taxonomic discussion, with some authors questioning its validity as a nomen ambiguum, while others have accepted it. The type material for the species has been a point of contention, with some references to a Lobel plate not cited in the original description. Original specimens in certain herbaria have been identified as S. emersum Rehmann, but other possibilities for lectotypification remain.