Juncus hesperius
Coast or bog rush
(c) Bob Miller, some rights reserved (CC BY) · licence
Family: Juncaceae · Type: Perennial · Native
Juncus hesperius (Coast or bog rush) is a native California perennial in the Juncaceae family, recognized by coastal habitat, rough stems, and dark-striped perianth pressed to dark fruit.
Coast or bog rush is a California native perennial found in northern coastal, Klamath Ranges, central coastal, and southern coastal ranges on damp ground, bogs, shores, and upper edges of salt marshes at elevations generally below 100 meters. Flowering from late spring to summer, this rush produces small dark brown to black-striped flowers with three stamens. Growing in dense tufts up to 115 centimeters tall with stems 0.8 to 2 millimeters wide, it develops rough stems with solid pith. Its leaf sheaths are 5 to 15 centimeters long, with mid-brown bases and gradually converging veins that terminate in a broadly asymmetrical winged summit. The fruit is a shiny, dark brown to nearly black oblong structure measuring 1.9 to 2.1 millimeters long, with three internal chambers.
Identification and appearance
Key characters: 53 sympatric species; key features are coastal habitat, rough stems, and dark-striped perianth pressed to dark fruit
Habitat and range
Habitat: Damp ground, bogs, shores, upper edges of salt marshes
Elevation: generally < 100 m
California counties: Del Norte, Humboldt, Marin, Mendocino, Monterey, San Francisco, Santa Cruz, Sonoma, Santa Barbara, San Luis Obispo, Siskiyou, San Mateo, Santa Clara
Outside California: to British Columbia
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 hesperius native to California?
Yes. Juncus hesperius is native to California (recorded as native).
Where in California does Juncus hesperius grow?
Juncus hesperius occurs in Del Norte, Humboldt, Marin, Mendocino, Monterey, San Francisco, Santa Cruz, Sonoma and other counties, at elevations of generally < 100 m.
What plant family does Juncus hesperius belong to?
Juncus hesperius is in the Juncaceae family, genus Juncus.
What habitat does Juncus hesperius grow in?
Juncus hesperius grows in Damp ground, bogs, shores, upper edges of salt marshes.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.