Juncus ensifolius
Dagger rush, swordleaved rush, Swordleaved Rush
(c) Matt Lavin, some rights reserved (CC BY) · licence
Family: Juncaceae · Type: Grass · Native
Juncus ensifolius (Dagger rush) is a native California grass in the Juncaceae family, recognized by key diagnostic feature is flat, curved, dagger-like leaves.
Dagger rush is a California native perennial found in northwestern California, the Cascade Range, Sierra Nevada, central coast, Transverse Ranges, and Great Basin in wet places at elevations below 2,800 meters. Flowering during the summer months, this plant produces dark brown to black flowers in dense, hemispheric clusters. Growing 20 to 60 centimeters tall with a slender, creeping rhizome, it develops flat, curved leaves 2 to 5 millimeters wide that arch toward the stem. Its leaves emerge primarily from the base, with overlapping leaf bases and long, distinctive tips. The plant produces oblong fruits with short beaks that typically exceed the length of its perianth parts.
Identification and appearance
Key characters: 70 sympatric species; key diagnostic feature is flat, curved, dagger-like leaves
Habitat and range
Habitat: Common. Wet places
Elevation: < 2800 m
California counties: Humboldt, Los Angeles, Napa, Plumas, San Benito, San Bernardino, Shasta, Siskiyou, Trinity, Tulare, Inyo, Sierra, Alpine, Butte, Colusa, Del Norte, El Dorado, Fresno, Glenn, Mariposa, Modoc, Mono, Monterey, Nevada, Tehama, Tuolumne, Kern, Placer, Yuba, Amador, Sonoma, Lassen, Lake, Mendocino, Ventura, Calaveras, Santa Barbara, San Mateo
Outside California: to Alaska, western Canada, Utah, northeastern Asia, Mexico
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 ensifolius native to California?
Yes. Juncus ensifolius is native to California (recorded as native).
Where in California does Juncus ensifolius grow?
Juncus ensifolius occurs in Humboldt, Los Angeles, Napa, Plumas, San Benito, San Bernardino, Shasta, Siskiyou and other counties, at elevations of < 2800 m.
What plant family does Juncus ensifolius belong to?
Juncus ensifolius is in the Juncaceae family, genus Juncus.
What habitat does Juncus ensifolius grow in?
Juncus ensifolius grows in Common. Wet places.
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.