Sparganium

Scientific name

Sparganium L.

Common names

bur-reed

Family

Sparganiaceae

Could be confused with

Acorus, Butomus, Carex, Cyperus, Iris, Typha

Native distribution

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.

Adventive distribution

Sparganium erectum is introduced into Australia.

Weed status

Sparganium erectum is an aquatic weed on the U.S. federal noxious weed list.

Habit

emergent, narrow-leaved rosette plant

Brief description

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.

Natural habitat

still waters of swamps, ponds, lakes, and rivers

Additional comments

a circumboreal genus with some species also present in Australia and Asia; closely related to Typha