Page author: Don Knoke
Juncus mertensianus
Mertens' rush

Distribution: Alaska to California, east to Alberta, South Dakota and New Mexico

Habitat: Wet places along streams and lakes, mid- to high elevations in the mountains

Flowers: July - September

Origin: Native

Conservation Status: Not of concern


Rhizomatous perennial, the stems clustered, somewhat flattened, 1-2.5 dm. tall.


Leaves alternate, the stem leaves 1-4, the blades semi-terete, with prominent partitions; leaf bases sheathing, the sheathes projecting into rounded or acute, membranous auricles 1-2 mm. long.


Flowers numerous in a terminal, capitate cluster up to 2 cm. broad, the involucral bract shorter to much longer than the head; perianth 3-4 mm. long, the 6 segments dark brown, narrowly lanceolate and somewhat awl-shaped; stamens 6, the anthers shorter than the filaments.


Capsule about equal to the perianth, cylindric-obovoid, abruptly truncate.

Accepted Name:
Juncus mertensianus Bong.
Publication: Mém. Acad. Imp. Sci. St.-Pétersbourg, Sér. 6, Sci. Math. 2: 167. 1833. 1833.

Synonyms & Misapplications:
Juncus duranii Ewan
Juncus mertensianus Bong. var. duranii (Ewan) F.J. Herm.
Juncus mertensianus Bong. var. filifolius Suksd.
Juncus slwookoorum S. Young
Additional Resources:

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

WA Flora Checklist: Juncus mertensianus checklist entry.

E-Flora BC: Juncus mertensianus atlas page.

CalPhotos: Juncus mertensianus photos.

USDA Plants: Juncus mertensianus information.

26 photographs:
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