Scientific name

Acorus L.

Common names




Could be confused with

Carex, Cyperus, other sedges, Iris, Juncus, Sparganium, Vallisneria

Native distribution

widespread in tropical and subtropical regions of the world

Species commonly cultivated

Acorus calamus L. (and varieties) (Asia and North America)

A. gramineus Sol. (and varieties) (Asia)

Adventive distribution

introduced into Europe and South America

Weed status

not recorded as weedy


reed-like, emergent

Brief description

Perennial. Erect plant with creeping rhizome. Leaves in two sheathed rows, opposite distichous, equitant, linear, aromatic, with prominent midrib. Inflorescence a spadix, yellow-green, borne on stem that is fused with a leaf, arising approximately midway along leaf length. Spadix elongate, with numerous tiny bisexual flowers, spathe absent.

Natural habitat

marshes, swamps, and open ponds

Additional comments

Acorus is often regarded as a close relative of the Arum family (Araceae) and is sometimes included in that family. This plant has been found to have various medicinal, insecticidal, and pharmacological qualities. Acorus spp. are used primarily as pond plants.