Juncus effusus subsp. effusus
Common rush, Common Rush
Photo: parent species Juncus effusus · (c) Douglas Goldman, some rights reserved (CC BY-SA) · licence
Family: Juncaceae · Type: Perennial · Not Native
Juncus effusus subsp. effusus (Common rush) is a non-native California perennial in the Juncaceae family, recognized by non-native status, fine ridges, and spreading perianth.
Common rush is a naturalized perennial found in northern Sierra Nevada, central Valley, and high Cascade Range bioregions in lakeshores, wet pastures, and disturbed damp ground at elevations below 1,700 meters. With no specific flowering data available, this plant has pale brown perianth structures with delicate spreading characteristics. Growing with robust stems up to 105 centimeters tall and 2 to 5 millimeters wide, it features 14 to 26 fine ridges along each stem side and a solid internal pith. Its leaf sheaths range from 5 to 14 centimeters long, with deep brown coloration below and green to pale brown upper sections, displaying thin margins often dark-banded and converging at a broad summit. The fruit is small, measuring 1.7 to 2 millimeters long, oblong-truncate, and brown with concave partitions united only at the base.
Identification and appearance
Key characters: 53 sympatric species; key features are non-native status, fine ridges, and spreading perianth
Habitat and range
Habitat: Lakeshores, wet pastures, disturbed damp ground
Elevation: < 1700 m
Outside California: to Alaska, eastern North America, native to Eurasia
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 effusus subsp. effusus native to California?
No. Juncus effusus subsp. effusus is not native to California (recorded as not native).
What plant family does Juncus effusus subsp. effusus belong to?
Juncus effusus subsp. effusus is in the Juncaceae family, genus Juncus.
What habitat does Juncus effusus subsp. effusus grow in?
Juncus effusus subsp. effusus grows in Lakeshores, wet pastures, disturbed damp ground.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.