Potamogeton

Scientific name

Potamogeton L.

Common names

pond weed

Family

Potamogetonaceae

Similar genera

Aponogeton, Callitriche, Echinodorus, Heteranthera, Hydrocleys, Najas

Native distribution

cosmopolitancosmopolitan:
(adj) essentially worldwide in distribution

Species cultivated

Potamogeton crispus L.

P. gayii A. Benn.

P. illinoensis Morong

P. octandrus Poir.

P. schweinfurthii A. Benn.

P. wrightii Morong

Stuckenia pectinata (L.) Börner

Adventive distribution

Potamogeton crispus is introduced into North America, New Zealand and southern South America.

P. perfoliatus L. is introduced into Australia and New Zealand.

Weed status

Numerous species of Potamogeton have been recorded as troublesome: P. nodosus, P. crispus, and Stuckenia pectinata (L.) Börner (formerly Potamogeton pectinatus) are problematic in irrigation systems in several countries.

Habit

submersed, ascending stem plantstem plant:
(n) (a term used in the aquarium and pond plant trade) having an elongate stem (as opposed to a compact stem)
, often with floating leaves

Brief description

Perennial perennial:
(adj) (of a plant) having a life cycle of more than two years
or annual. Stem rhizomatousrhizomatous:
(adj) possessing rhizomes
or stoloniferous, bearing specialized tubers (turions); vertical stems produced at nodes along horizontal stem. Leaves alternatealternate:
(adj) (of leaves) bearing one leaf per node; placed singly on the stem at different heights
or rarely oppositeopposite:
(adj) (of leaves) two leaves per node; in pairs on opposite sides of an axis
; submergedsubmerged:
(adj) (syn. submersed) under water; submerged below the water surface
leaves thin, linear to lanceolatelanceolate:
(adj) lance-shaped; widest point below the middle, tapering to the apex
, marginmargin:
(n) edge; rim
entireentire:
(adj) having a continuous margin that is not toothed or lobed
, sometimes undulateundulate:
(adj) (of, e.g., a margin) with a wavy surface; wavy in the vertical (up and down) plane
; floating leaves (when present) thick, leathery, ovateovate:
(adj) egg-shaped in outline; generally with the broad end at or near the base
, ellipticelliptic:
(adj) in the form of an ellipse (oval)
, oblongoblong:
(adj) two to four times longer than wide, with +/- parallel sides
. Inflorescenceinflorescence:
(n) the arrangement of flowers on the floral axis
an emergentemergent:
(adj) (syn. emersed) with parts raised out of the water; extending up out of the water
spike. Flowers small, bisexualbisexual:
(adj) having both male and female sexual reproductive structures on one individual or in one flower
; 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 4 tepals. Dispersal by rhizomerhizome:
(n) an underground stem, usually growing horizontally, from which both roots and shoots emerge directly; the thick, above-ground stem of ferns
, stem fragments and seed.

Natural habitat

still or slow-flowing waters of lakes, rivers, and streams

Additional comments

A diverse genus in which many species form dense monoclonal stands. Stuckenia pectinata (Sago pondweed) is sometimes included in Potamogeton.