Bolboschoenus glaucus
Tubered bulrush
(c) Millie Basden, some rights reserved (CC BY) · licence
Family: Cyperaceae · Type: Grass · Not Native
Bolboschoenus glaucus (Tubered bulrush) is a non-native California grass in the Cyperaceae family, recognized by non-native status, small size, narrow leaves, and sinking fruits.
Tubered bulrush is a naturalized perennial found in the Great Valley, Central Coast, San Francisco Bay, and Southern California regions in fresh to brackish marshes, shores, and wildlife refuges at elevations below 800 meters. Flowering during summer, this plant produces yellow-anthered flowers in dense clusters of 3 to 30 spikelets 10 to 40 millimeters long. Growing to 150 centimeters tall with stems 1.5 to 3 millimeters in diameter, it forms dense stands in wetland habitats. Its leaves have sheath tips with acutely triangular membranous areas and blades 2 to 6 millimeters wide. The fruit is small and uniquely adapted to aquatic environments, sinking when submerged and measuring 2.5 to 3.3 millimeters long.
Identification and appearance
Key characters: 3 sympatric species; key features are non-native status, small size, narrow leaves, and sinking fruits
Habitat and range
Habitat: In dense stands locally. Fresh to brackish marshes, shores, wildlife refuges, rice-fields
Elevation: < 800 m
California counties: Colusa, San Luis Obispo, Riverside, Butte, Solano, Kern, Merced, Glenn, Sonoma, Yolo, Tehama, San Diego, Marin, Contra Costa, Napa, Alameda
Outside California: to Oregon, Idaho, New York, Eurasia, Africa
Bloom period
Bolboschoenus glaucus blooms Summer.
How to tell it apart
vs Schoenoplectus: Dig for tubers - Bolboschoenus has firm tubers, Schoenoplectus has only fibrous roots or rhizomes.; vs Carex: Bolboschoenus flowers are in rounded spikelets, Carex has separate male/female spikes or combined in same spike.; vs Scirpus: Bolboschoenus has firm underground tubers, Scirpus lacks tubers entirely.; vs Cyperus: Bolboschoenus has three-angled stems, Cyperus typically has flat leaf-like bracts radiating umbrella-like at top.; vs Sporobolus: Bolboschoenus stems are three-angled and solid, grass stems are round and hollow with nodes.
Frequently asked questions
Is Bolboschoenus glaucus native to California?
No. Bolboschoenus glaucus is not native to California (recorded as not native).
When does Bolboschoenus glaucus bloom?
Bolboschoenus glaucus blooms Summer.
Where in California does Bolboschoenus glaucus grow?
Bolboschoenus glaucus occurs in Colusa, San Luis Obispo, Riverside, Butte, Solano, Kern, Merced, Glenn and other counties, at elevations of < 800 m.
What plant family does Bolboschoenus glaucus belong to?
Bolboschoenus glaucus is in the Cyperaceae family, genus Bolboschoenus.
What habitat does Bolboschoenus glaucus grow in?
Bolboschoenus glaucus grows in In dense stands locally. Fresh to brackish marshes, shores, wildlife refuges, rice-fields.
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.