Page authors: Don Knoke, David Giblin
Juncus bulbosus
bulbous rush, spreading rush

Distribution: Occurring west of the Cascades crest in Washington; British Columbia to Oregon, east across northern Canada to the Atlantic Coast.

Habitat: Sandy or peaty shores of streams, and pools.

Flowers: July-September

Origin: Introduced from Eurasia

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Wind


Tufted perennial, often with basal bulb-like swellings, the stems 0.3-3 dm. tall, often up to 10 dm. when floating or submersed; the stems erect to decumbent and rooting at the nodes, or floating, terete and smooth.


Leaves 1-2, the blades terete, lax, 2-10 cm. long and 0.8-1.4 mm. broad; leaf bases sheathing, forming auricles 0.4-1 mm. long, acute and scarious.


Inflorescence of terminal racemes of 1-8 heads, 2-10 cm. long, erect, the heads 2- to 6-flowered, obconic; flowers often forming bulbils; perianth 2-3.6 long, the 6 segments subequal, pale brown, ovate to lanceolate; stamens 3 or 6,


Capsule cylindric, 2.5-4 mm. long, chestnut brown, the apex obtuse.

Accepted Name:
Juncus bulbosus L.
Publication: Sp. Pl. 1: 327. 1753.

Synonyms & Misapplications:
Juncus kockii F.W. Schultz
Juncus supinus Moench [HC]
Additional Resources:

PNW Herbaria: Specimen records of Juncus bulbosus in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Juncus bulbosus checklist entry

OregonFlora: Juncus bulbosus information

E-Flora BC: Juncus bulbosus atlas page

CalPhotos: Juncus bulbosus photos

4 photographs:
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