Scientific name

Iris L.

Common names




Could be confused with

Acorus, Sparganium, Typha

Native distribution

northern temperate

Species commonly cultivated

Iris ensata Thunb. (Asia) and cultivars

I. fulva Ker Gawl. (central U.S.) and hybrids (Louisiana hybrids)

I. laevigata Fisch. (East Asia) and cultivars

I. pseudacorus L. (Europe, Asia, North Africa)

I. virginica L. (eastern U.S.)

Adventive distribution

Numerous terrestrial species are introduced into many countries; many aquatics are established beyond botanical gardens, etc. Iris pseudacorus L. is introduced into the United States from Europe.

Weed status

Iris douglasiana Herbert and I. missouriensis Nutt. are regulated in California (United States); I. pseudacorus is regulated in Vermont (United States).


emergent rosette plant

Brief description

Perennial. Creeping rhizome. Leaves rigid, flat, smooth and elongate-linear, distichous, equitant, overlapping each other but appearing to be in a rosette. Inflorescence a solitary flower or panicle. Flowers large, showy, subtended by a spathe-like bract; perianth of 6 tepals in 2 similar series; outer series deflexed, inner series erect. Dispersal by rhizome division and seeds.

Natural habitat

wet ground and littoral region of lakes, swamps, and rivers

Additional comments

A genus containing over 300 species and many cultivated varieties. Most aquatic species belong to the section Apogon.