Butomus umbellatus L.
Butomaceae (Flowering Rush family)

Introduction to Vascular Plants


© Bruce Bennett     (Photo ID #22939)


E-Flora BC Static Map

Distribution of Butomus umbellatus
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Flowering rush is an introduced species in North America that originates in Eurasia, and was brought to North America as an ornamental plant in water gardens. It is now found across the northern US states from Idaho to Vermont, and in Canada (AB, BC, MB, NB, NS, ON, PE, QC) (USDA 2010). While it is often rare in its native range, it has become a serious pest where it is introduced, including in the Great Lakes area. In British Columbia, it is known from only two locales: Hatzic Lake near Mission and a single location in Surrey, on West Creek, and may be more frequent but overlooked. This is a distinctive flowering plant species. It is a relatively tall (100-150 cm) rhizomatous (thick rhizomes) perennial that is rush-like in appearance (narrow leaves) with an umbel of pink flowers. It inhabits shorelines but can tolerate deeper water to depths of 2 m (Global Invasive Species Database 2010). It flowers through the summer from June to August.

Species Information

Perennial aquatic herb from a stout rhizome; stems solitary, 100-150 cm tall.
All basal, erect or floating in deep water, linear, twisted, 50-100 cm long, 0.5-1 cm wide.
Inflorescence of numerous flowers on slender stalks in an umbel; perianth 2-2.5 cm wide, long-stalked, the stalks 5-10 cm long, subtended by narrowly triangular bracts; petals 3, pink, more deeply coloured on the outside; sepals 3, greenish outside along the midribs, nearly as long as the petals; stamens 9.
Follicles, 6, beaked, about 1 cm long; seeds straight, lined.

SourceThe Illustrated Flora of British Columbia


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Habitat and Range

Marshes and lakeshores; rare in SW BC, known only from Hatzic Lake; introduced from Eurasia.

SourceThe Illustrated Flora of British Columbia