Juncus tiehmii
Tiehm's rush, Tiehm's Rush
Family: Juncaceae · Type: Grass · Native
Juncus tiehmii (Tiehm's rush) is a native California grass in the Juncaceae family, recognized by tiny size, 4 perianth parts, and few stamens diagnostic.
Tiehm's rush is a California native annual found in the Sierra Nevada, Transverse Ranges, Mojave Desert, and Peninsular Ranges in moist granitic sand of seeps, streambanks, and meadows at elevations of 300 to 3,100 meters. Tiny and densely clustered, this delicate rush produces pale green or pink flowers in small clusters with 1 to 7 flowers per stem. Growing as a compact, dense tussock just 0.5 to 6 centimeters tall with extremely slender stems less than 0.2 millimeters wide, it forms intricate miniature clumps. Its basal leaves are short, measuring less than 2.5 centimeters long, with no sheath appendages. The fruit is generally longer than the perianth, with seeds that are distinctively striate and small, measuring just 0.3 to 0.5 millimeters long.
Identification and appearance
Key characters: 52 sympatric species; tiny size, 4 perianth parts, and few stamens diagnostic
Habitat and range
Habitat: Bare, moist granitic sand of seeps, streambanks, meadows
Elevation: 300-3100 m
California counties: Los Angeles, Riverside, San Bernardino, San Diego, Kern, San Luis Obispo, Sierra, Tulare, Tuolumne, Inyo, Monterey, Modoc, Siskiyou, Lassen, Fresno, Mono, Ventura, Placer
Outside California: to Washington, Idaho, Nevada, Baja California
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 tiehmii native to California?
Yes. Juncus tiehmii is native to California (recorded as native).
Where in California does Juncus tiehmii grow?
Juncus tiehmii occurs in Los Angeles, Riverside, San Bernardino, San Diego, Kern, San Luis Obispo, Sierra, Tulare and other counties, at elevations of 300-3100 m.
What plant family does Juncus tiehmii belong to?
Juncus tiehmii is in the Juncaceae family, genus Juncus.
What habitat does Juncus tiehmii grow in?
Juncus tiehmii grows in Bare, moist granitic sand of seeps, streambanks, meadows.
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.