Juncus bulbosus
Bulbous rush
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Family: Juncaceae · Type: Grass · Not Native
Juncus bulbosus (Bulbous rush) is a non-native California grass in the Juncaceae family, recognized by . Key features: rhizome knobby and fragile, rooting nodes forming plantlets.
Bulbous rush is a naturalized perennial found in the northern California coast region, specifically Mendocino County, in marshes and ponds at elevations below 100 meters. When flowering, this rush produces dark petals that are ovate to lanceolate, with tiny clusters of 3 to 16 flowers. Growing in matted clusters 1 to 30 centimeters tall, it forms distinctive emergent stems that can root at the nodes and create new plantlets. Its early submerged leaves are hair-like and less than 20 centimeters long, with cylindrical blades containing multiple air chambers. The plant produces small oblong fruits 2 to 3.5 millimeters long with tiny seed appendages, characteristic of its adaptable aquatic growth habit.
Identification and appearance
Key characters: 26 sympatric species. Key features: rhizome knobby and fragile, rooting nodes forming plantlets
Habitat and range
Habitat: Marshes, ponds
Elevation: < 100 m
Outside California: introd. OR to BC, e N.Am, Australasia, native to Eur, n Afr
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 bulbosus native to California?
No. Juncus bulbosus is not native to California (recorded as not native).
What plant family does Juncus bulbosus belong to?
Juncus bulbosus is in the Juncaceae family, genus Juncus.
What habitat does Juncus bulbosus grow in?
Juncus bulbosus grows in Marshes, ponds.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.