Page authors: Don Knoke, David Giblin
Butomus umbellatus
flowering rush

Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon, east across the northern U.S. and Canada to the Atlantic Coast.

Habitat: Shorelines of major rivers, wetlands, and ponds.

Flowers: July-September

Origin: Introduced from Eurasia

Conservation Status: Not of concern


Plants of fresh water, the stems to 150 cm. long.


Leaves linear, to 2.7 m. long, the blade triangular at the base, submersed, emersed or floating.


Inflorescence an umbel with 20-25 flowers on a triangular scape up to 150 cm. long; bracts 3, subtending the umbel; pedicles 4-10 cm.; flowers 2-2.5 cm. wide; outer 3 tepals elliptic, 6-7.5 mm. long and 2-2.5 mm. wide; inner 3 tepals oblanceolate, 9-11.5 mm. long and 4.5-6 mm wide; tepals light purple with darker purple veins; stamens 3 pairs opposite outer tepals and 3 opposite inner tepals; pistils pink.


Follicles leathery, 1 cm. long.

Accepted Name:
Butomus umbellatus L.
Publication: Sp. Pl. 1: 372. 1753.

Synonyms & Misapplications:
Butomus junceus Turcz.
Butomus umbellatus L. f. vallisneriifolius (Sagorski) Glnck
Additional Resources:

PNW Herbaria: Specimen records of Butomus umbellatus in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Butomus umbellatus checklist entry.

E-Flora BC: Butomus umbellatus atlas page.

CalPhotos: Butomus umbellatus photos.

USDA Plants: Butomus umbellatus information.

16 photographs:
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