Juncus triformis
Yosemite dwarf rush
(c) James C. Davis, some rights reserved (CC BY-SA), uploaded by James C. Davis · licence
Family: Juncaceae · Type: Grass · Native
Juncus triformis (Yosemite dwarf rush) is a native California grass in the Juncaceae family, recognized by hair-like stems, reddish color in fruit, and long anthers diagnostic.
Yosemite dwarf rush is a California native annual found in the Cascade Ranges, Sierra Nevada, southern California coastal areas, San Bernardino Mountains, and Peninsular Ranges in vernal pools, swales, and volcanic and granitic seeps at elevations of 50 to 2,500 meters. Typically flowering when conditions permit, this plant produces tiny flowers with green to red perianth parts arranged sparsely along delicate stems. Growing as a dense tufted plant just 2 to 16 centimeters tall with hair-like stems less than 0.4 millimeters wide, it forms compact clusters close to the ground. Its basal leaves are short, measuring less than one-third of the stem length, with no sheath appendages. The fruit is spheric to oblong, generally smaller than the perianth and often reddish, containing 2 to 3 seed chambers.
Identification and appearance
Key characters: 57 sympatric species; hair-like stems, reddish color in fruit, and long anthers diagnostic
Habitat and range
Habitat: Vernal pools, swales, volcanic and granitic seeps
Elevation: 50-2500 m
California counties: Fresno, San Bernardino, San Diego, Shasta, Tulare, Tuolumne, Madera, Butte, Mariposa, Riverside, Tehama, Placer
How to tell it apart
vs Schoenoplectus: Juncus has leaf blades present; Schoenoplectus is leafless with only bladeless sheaths at base.; vs Carex: Juncus has round or flattened stems; Carex has triangular stems you can feel.; vs Luzula: Run finger along leaf edge - smooth = Juncus, hairy = Luzula.; vs Elegia: Juncus has small individual flowers; Elegia has showy papery bracts and branching structure.; vs Cyperus: Juncus has round stems and capsules; Cyperus has triangular stems and lens-shaped achenes.
Frequently asked questions
Is Juncus triformis native to California?
Yes. Juncus triformis is native to California (recorded as native).
Where in California does Juncus triformis grow?
Juncus triformis occurs in Fresno, San Bernardino, San Diego, Shasta, Tulare, Tuolumne, Madera, Butte and other counties, at elevations of 50-2500 m.
What plant family does Juncus triformis belong to?
Juncus triformis is in the Juncaceae family, genus Juncus.
What habitat does Juncus triformis grow in?
Juncus triformis grows in Vernal pools, swales, volcanic and granitic seeps.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.