Sparganium

Scientific name

Sparganium L.

Common names

bur-reed

Family

Typhaceae

Similar genera

Acorus, Butomus, Carex, Cyperus, Iris, Typha

Native distribution

Northern Hemisphere, Asia, Australia

Species cultivated

Sparganium americanum Nutt.l

S. androcladum (Engelm.) Morong

S. erectum L.

S. eurycarpum Engelm. in A. Gray

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.

See Sparganium erectum disseminule fact sheet.

Adventive distribution

Sparganium erectum is introduced into Australia and the United States.

Weed status

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

Habit

emergent, narrow-leaved rosetterosette:
(n) a radiating cluster of leaves, usually close to the ground at the base of a plant
plant

Brief description

Perennial. Stem compact and corm-like, rhizomatousrhizomatous:
(adj) possessing rhizomes
. Leaves submergedsubmerged:
(adj) (syn. submersed) under water; submerged below the water surface
, floating, or emergentemergent:
(adj) (syn. emersed) with parts raised out of the water; extending up out of the water
, distichousdistichous:
(adj) (of leaves or flowers) distinctly arranged in two ranks along an axis; leaves may be opposite or alternate
, sheathed below, linear. Flowers in globoseglobose:
(adj) spherical or nearly so
unisexual heads arranged in simple or branched racemes; heads sessilesessile:
(adj) attached directly, without a stalk
or peduncled, subtended by bracts; female heads below males. Perianthperianth:
(n) collective term for the calyx and corolla of a flower; also used for floral whorl(s) in which the calyx and corolla cannot be resolved; any of the leaves or bracts surrounding the sex organs of bryophytes
of 3-6 tepals. Dispersal by seed or rhizomerhizome:
(n) an underground stem, usually growing horizontally, from which both roots and shoots emerge directly; the thick, above-ground stem of ferns
division.

Natural habitat

still waters of swamps, ponds, lakes, and rivers

Additional comments

A circumborealcircumboreal:
(adj) (of plants) found all around the world in the Northern Hemisphere
genus with some species also present in Australia and Asia; closely related to Typha.