Alisma

Scientific name

Alisma L.

Common names

water plantain, mad dog weed, mud plantain

Family

Alismataceae

Similar genera

Echinodorus, Orontium, Sagittaria

Native distribution

Northern Hemisphere

Species cultivated

Alisma lanceolata With.

A. plantago-aquatica L.

A. subcordatum Raf.

Adventive distribution

almost cosmopolitan

Weed status

Alisma plantago-aquatica and A. lanceolata are often weeds in rice fields in various countries.

Habit

emergent, broad-leaved rosette

Brief description

Annual or perennial. Stem a short rhizomatous corm. Leaves in a basal rosette, erect, petiolate, linear to ovate, venation palmate with numerous cross veins; base rounded or cordate; margin entire; juvenile leaves submersed. Inflorescence a compound cyme or panicle of successive whorls of 3 or more branches of flowers. Flowers bisexual, with 3 green sepals and 3 white to pink petals with yellowish spot at base of petal; stamens 6, in 3 pairs; carpels numerous, in 1 circular to triangular whorl. Dispersal by seed.

Natural habitat

shallow marginal water of lakes, rivers, streams, swamps, and wet ground

Additional comments

A genus of eight accepted species, and an additional three accepted hybrids; at least two species are used as pond plants.