Monochoria vaginalis (Burm. f.) K. Presl ex Kunth


Monochoria vaginalis is an aquatic herbaceous plant native to temperate and tropical Asia. Plant size, leaf shape, and flower number in M. vaginalis are highly dependent on the amount of water available. It can be annual or perennial. It has a short rhizome. M. vaginalis can grow from 4-20 in. (10-50 cm) tall and is stemless.
Two types of leaves are seen. The sessile leaves are up to 2 in. (5 cm) long. The blade is linear with an acuminate apex. Petiolate leaves are cordate with a soft hollow petiole from 3-11 in. (7-28 cm) long.
The flowers of M. vaginalis are few to numerous in racemes 0.79-1.6 in. (2-4 cm) long. In California racemes usually bear 2-8 flowers. The peduncles emerge from the sheath of the upper-most leaf.
Fruits are ellipsoid 3-valved capsules about 0.4 in. (1 cm) long. The numerous oblong seeds have 8-12 longitudinal ribs.
Ecological Threat
Monochoria vaginalis is listed as a Federal Noxious Weed. It has been reported in California and Hawaii. It is often seen as a weed in rice fields.

Selected Images


EDDMapS Distribution

EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit

State Regulated List

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Liliopsida
Subclass: Liliidae
Order: Liliales
Family: Pontederiaceae
Genus: Monochoria
Subject: Monochoria vaginalis (Burm. f.) K. Presl ex Kunth

Synonyms and Other Names

Other Common Names:
heartshape false pickerelweed, heartshape falsepickerelweed, pickerel weed


Plants - Forbs/Herbs