Pontederia

Scientific name

Pontederia L.

Common names

pickerel weed

Family

Pontederiaceae

Similar genera

Eichhornia, Monochoria, Schumannianthus, Thalia

Native distribution

America

Species cultivated

Pontederia cordata L.

P. rotundifolia L.f.

Adventive distribution

Australia, Europe, Africa, western North America

Weed status

Pontederia rotundifolia L.f. is known to be a prohibited aquatic plant in at least one country.

Habit

emergentemergent:
(adj) (syn. emersed) with parts raised out of the water; extending up out of the water
broad leaved rosetterosette:
(n) a radiating cluster of leaves, usually close to the ground at the base of a plant
plant

Brief description

Perennial. Stems floating, creeping or ascending (mature plants usually emergentemergent:
(adj) (syn. emersed) with parts raised out of the water; extending up out of the water
), stoloniferous or rhizomatousrhizomatous:
(adj) possessing rhizomes
, roots produced at nodes. 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
, alternatealternate:
(adj) (of leaves) bearing one leaf per node; placed singly on the stem at different heights
, in compact rosettes, petiolatepetiolate:
(adj) relating to or in the form of a petiole; bearing petioles
or sessilesessile:
(adj) attached directly, without a stalk
; leaf bladeblade:
(n) (syn. lamina) the flat, expanded part of a leaf, frond, or petal (excluding, e.g., the petiole)
linear to ellipticelliptical:
(adj) in the form of an ellipse (oval)
or ovateovate:
(adj) egg-shaped in outline; generally with the broad end at or near the base
, venationvenation:
(n) the arrangement of veins in a leaf
parallel; base sagittatesagittate:
(adj) shaped like an arrowhead
to cordatecordate:
(adj) heart-shaped; in the form of two rounded lobes
. Inflorescenceinflorescence:
(n) the arrangement of flowers on the floral axis
an elongate or globoseglobose:
(adj) spherical or nearly so
, prostrateprostrate:
(adj) growing closely along the ground
or erect spikespike:
(n) an indeterminate, unbranching inflorescence of sessile flowers or flower clusters on a usually elongated axis
, subtended by 2 spathes; spathes dissimilar: upper scalescale:
(n) any thin, usually small and dry, membranous to leathery bract
-like, lower leaf-like. Tubulartubular:
(adj) (of a corolla, perianth, calyx tube or other structure) (1) tube-shaped; cylindrical: narrow and elongate with more or less straight sides; (2) having segments fused into a tube (of any shape)
perianth of 6 tepals in 2 whorls of 3, tubulartubular:
(adj) (of a corolla, perianth, calyx tube or other structure) (1) tube-shaped; cylindrical: narrow and elongate with more or less straight sides; (2) having segments fused into a tube (of any shape)
, 2-lipped, blue to purple; median inner lobe larger than rest, often with yellow fleck. Seeds with spiny ridges. Dispersal by seed or stem fragments.

Natural habitat

swamps, rivers, lakes, and streams

Additional comments

Pontederia (including Reussia Endler) contains approximately six species, with P. cordata being most commonly available. Several varieties of P. cordata are cultivated.