Butomus umbellatus L.


Butomus umbellatus is a perennial which spreads primarily from rhizomes. This aquatic plant invades along the margins of slow moving waterways. This plant can reach from 1-5 ft. (0.3-1.5 m) in height and can survive in water of up to 9.8 ft. (3 m) deep. It does not tolerate salt water.
The leaves are linear, up to 3.2 ft. (1 m) long and triangular and fleshy in cross-section. The leaves may be erect or floating on the surface of the water.
Flowering occurs in June to August, when umbels of small, 0.75-1 in. (1.9-2.5 cm) wide, pink to white flowers develop.
The fruit is beaked which split at maturity to release the seeds. The seeds float which allows them to be easily dispersed by water.
Ecological Threat
This plant spreads mostly from rhizomes and occurs in wet areas with muddy soil, such as freshwater marshlands, lakes and streams. Butomus umbellatus can displace native riparian vegetation. It can form dense stands which are an obstacle to boat traffic. It is tolerant of a wide range of temperatures which gives it the potential to invade across much of the United States. Butomus umbellatus is native to Eurasia and was first found in Canada in the late 1800’s and in the United States in the early 1900’s.


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 www.eddmaps.org

State Regulated List

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

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Liliopsida
Subclass: Alismatidae
Order: Alismatales
Family: Butomaceae
Genus: Butomus
Subject: Butomus umbellatus L.

Synonyms and Other Names

Other Common Names:
grassy rush, water gladiolus


Plants - Aquatic Plants