Sparganium L.
bur-reed
Typhaceae
Acorus, Butomus, Carex, Cyperus, Iris, Typha
Northern Hemisphere, Asia, Australia
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.
Sparganium erectum is introduced into Australia and the United States.
Sparganium erectum is an aquatic weed on the U.S. federal noxious weed list.
emergentemergent:
(adj) (syn. emersed) with parts raised out of the water; extending up out of the water
, narrow-leaved rosetterosette:
(n) a radiating cluster of leaves, usually close to the ground at the base of a plant
plant
Perennial. Stem compact and cormcorm:
(n) a shortened, subterranean bulb-like stem or part of the stem, often bearing scale-like leaves
-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
unisexualunisexual:
(adj) (of a flower) with either stamens (male) or pistils (female) but not both; consisting of only male or female flowers
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.
still waters of swamps, ponds, lakes, and rivers
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.