Common Name: Rocky Mountain rush

Duration: Perennial

Nativity: Native

Lifeform: Graminoid

General: Rhizomatous perennials, 20-60 cm tall, with rhizomes 2-3 mm in diameter.

Vegetative: Erect stems 2-3 mm in diameter, 0-2 cataphylls, straw-colored, with a narrowly acute apex; 1-3 basal leaves, 2-6 cauline leaves, all straw-colored, no auricles; blade 2-25 cm long by 1.5-4 mm wide.

Inflorescence: Panicles or racemes 2-14 cm long, with 2-20 heads or solitary heads, with erect or ascending branches, the primary branch erect, heads with 3-70 flowers, obovoid to globose, 7-11 mm in diameter; flowers with tepals, green to brown or reddish brown, lanceolate; outer tepals 2.5-3.5 mm, acuminate apex, inner tepals 2.2-3 mm, nearly equal; 6 stamens, with anthers ; capsules slightly exserted, ellipsoid, 2.5-4.5 mm.

Ecology: Found in wet meadows, bogs, along streams and lake shores from 1,500-10,000 ft (457-3048 m); flowers early summer-fall.

Notes: This is part of a species complex, with many geographically distinct varieties that all emerge from the former J. ensifolius complex. In our region, it is probably useful to distinguish this species and what was formerly J. ensifolius var. ensifolius. The only distinction between them is the latter has 3 stamens, while this species has 6 stamens. Morphologically they are really similar, and more to the point, FNA indicates that the species in our range is all of the same type.

Ethnobotany: Unknown, but other species in the genus have uses.

Etymology: Juncus comes from the Latin jungere, to join or bind, while saximontanus refers to being from rocks or mountains.

Synonyms: Juncus ensifolius var. brunnescens, J. ensifolius var. montanus, J. saximontanus var. robustior, J. xiphioides var. macranthus, J. xiphioides var. montanus

Editor: SBuckley, 2010

Leaves 2--25 cdm × 1.5--4 mm. Inflorescences 3--20 heads; heads obovoid to globose. Flowers: outer tepals 2.7--3.6 mm; inner tepals 2.7--3 mm; stamens 6. Capsules slightly exserted, ellipsoid, 2.4--4.3 mm. Seeds 0.4--1 mm, tailed or more often not tailed.

Fruiting early summer--fall. Wet meadows, bogs, springy woods, stream and lake shores; 400--3000 m; Alta., B.C.; Ariz.,, Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., S.Dak., Tex., Utah, Wash., Wyo.; Mexico (s to Puebla, Veracruz).