Butomus

Scientific name

Butomus L.

Common names

flowering rush, grassy rush, water-gladiolus

Family

Butomaceae

Could be confused with

Echinodorus, Juncus, Sagittaria, Sparganium, Typha

Native distribution

northern Africa, Asia, Europe

Species commonly cultivated

Butomus umbellatus L. (northern Africa, Asia, Europe)

Adventive distribution

North America

Weed status

declared an aquatic noxious weed in the United States in MN, NH, VT, and WA

Habit

rush-like plant, submerged or more commonly emergent

Brief description

Perennial. Leaves of emergent form grass-like, up to 100 cm or more long, triangular in cross-section, produced basally in 2 ranks from a fleshy rhizome; base acuminate. Inflorescence a many-flowered umbel, borne on a scape 1 to 1.5 m tall, above leaves, pedicels 5-10 cm long. Flowers actinomorphic, showy, perfect, pink; sepals 3, petaloid; petals 3; stamens 9 or 6. Dispersal by rhizome fragments.

Natural habitat

still or slowly moving water, marshes, shores of lakes, ponds, riverbanks, wet ground

Additional comments

The genus Butomus consists of only one species, B. umbellatus. Butomus is similar to members of Alismataceae (and is sometimes placed in that family) but differs in having only 6 carpels and 6-9 stamens.