Northern Hemisphere, Asia, Australia
Species commonly cultivated
Sparganium americanum Nutt.l (North America)
S. androcladum (Engelm.) Morong (North America)
S. erectum L. (circumboreal, Australia)
S. eurycarpum Engelm. in A. Gray (North America)
U.S. Federal Noxious Weed: Sparganium erectum
Identification: Features that may help to distinguish S. erectum from other species in the genus: the flowering stem is branched, and each branch has one or more female heads at the base, and several male heads further out. In other species the unbranched stem has all the female heads below all the male ones. S. erectum leaves and stems are upright, not floating.
Sparganium erectum is introduced into Australia.
Perennial. Stem erect and corm-like, rhizomatous. Leaves submerged, floating, or emergent, distichous, sheathed below, linear. Flowers in globose unisexual heads arranged in simple or branched racemes; heads sessile or peduncled, subtended by bracts; female heads below males. Perianth of 3-6 tepals. Dispersal by seed or rhizome division.
still waters of swamps, ponds, lakes, and rivers