Pontederia

Scientific name

Pontederia L.

Common names

pickerel weed

Family

Pontederiaceae

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

emergent broad leaved rosette plant

Brief description

Perennial. Stems floating, creeping or ascending (mature plants usually emergent), stoloniferous or rhizomatous, roots produced at nodes. Leaves submerged, floating or emergent, alternate, in compact rosettes, petiolate or sessile; leaf blade linear to elliptic or ovate, venation parallel; base sagittate to cordate. Inflorescence an elongate or globose, prostrate or erect spike, subtended by 2 spathes; spathes dissimilar: upper scale-like, lower leaf-like. Tubular perianth of 6 tepals in 2 whorls of 3, tubular, 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.