Page authors: Don Knoke, David Giblin
Sparganium eurycarpum
broadfruited bur-reed

Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Baja, California, east across most of North America to the Atlantic Coast.

Habitat: Wet meadows to shallow marshes, mostly emersed.

Flowers: May-October

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Wind


Dioecious, aquatic perennials from rhizomes, the stems erect, 6-12 dm. tall.


Leaves flat, slightly keeled beneath, 3-8 dm. long and 8-15 mm. broad.


Flowers in globose clusters toward the tip of the main stem; inflorescence branched, 1.5-4 dm. long, the branches with 5-12 staminate heads and 1-2 pistillate heads, the latter 20-26 mm. thick when mature; stamens 3-5 with 3-5 minute, chaffy bracts; pistil 1, the style 2-cleft; stigmas 2, linear, 2 mm. long.


Fruit a nutlet-like achene, 2-seeded, rounded, up to 10 mm. long, narrowed very abruptly to the stylar beak.

Accepted Name:
Sparganium eurycarpum Engelm.
Publication: Manual of Botany of the Northern United States (ed. 2). 430. 1856.

Synonyms & Misapplications:
Sparganium californicum Greene [Abrams]
Sparganium erectum L. ssp. stoloniferum (Buch.-Ham. ex Graebn.) C.D.K. Cook & M.S. Nicholls, homonym (illegitimate) [JPM]
Sparganium eurycarpum Engelm. ssp. eurycarpum [JPM]
Sparganium greenei Morong [Peck]
Additional Resources:

PNW Herbaria: Specimen records of Sparganium eurycarpum in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Sparganium eurycarpum checklist entry

OregonFlora: Sparganium eurycarpum information

E-Flora BC: Sparganium eurycarpum atlas page

CalPhotos: Sparganium eurycarpum photos

21 photographs:
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