Fimbristylis vahlii
Vahl's fimbristylis
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Family: Cyperaceae · Type: Grass · Native
Fimbristylis vahlii (Vahl's fimbristylis) is a native California grass in the Cyperaceae family.
Vahl's fimbristylis is a California native annual found in southern Sierra Nevada foothills, San Joaquin Valley, and eastern Sonoran Desert (Imperial County) in moist to wet soils, alluvial banks, and lake margins at elevations below 200 meters. Flowering from July to November, this delicate plant produces small white to tan spikelets in compact head-like clusters 2 to 5 millimeters long. Growing with extremely slender stems less than 0.5 millimeters in diameter and reaching 4 to 15 centimeters tall, it forms low, dense clumps without a rhizome. Its narrow leaves are less than 0.5 millimeters wide, smooth or slightly hairy-rough, with no ligule present. The fruit is a tiny white structure with sharp angles, approximately 0.5 to 0.7 millimeters long with distinctive transverse-rectangular cellular patterns.
Identification and appearance
Key characters: 0 sympatric species; geographically isolated in SNF, SnJV, DSon regions
Habitat and range
Habitat: Moist to wet soil, alluvial or mineralized banks, shores, fluctuating pond, lake margins
Elevation: < 200 m
California counties: Merced, Fresno, Tulare, Imperial, Kern, San Joaquin, Stanislaus, Kings, Madera
Outside California: to southeastern United States, South America
Bloom period
Fimbristylis vahlii blooms Jul-Nov.
How to tell it apart
vs Juncus: Fimbristylis has triangular stems and scabrous sheath edges; Juncus has round stems and smooth sheaths.; vs Bulbostylis: Fimbristylis has short sandpaper-like hairs on sheaths; Bulbostylis has long, soft, conspicuous fringe.; vs Bolboschoenus: Fimbristylis has scabrous sheath edges; Bolboschoenus has smooth sheaths and often has tubers.; vs Scirpus: Fimbristylis has distinctly rough, hairy sheath tips; Scirpus has smooth sheaths.; vs Calliscirpus: Fimbristylis has scabrous sheath tips; Calliscirpus has smooth sheaths and tufted growth.
Frequently asked questions
Is Fimbristylis vahlii native to California?
Yes. Fimbristylis vahlii is native to California (recorded as native).
When does Fimbristylis vahlii bloom?
Fimbristylis vahlii blooms Jul-Nov.
Where in California does Fimbristylis vahlii grow?
Fimbristylis vahlii occurs in Merced, Fresno, Tulare, Imperial, Kern, San Joaquin, Stanislaus, Kings and other counties, at elevations of < 200 m.
What plant family does Fimbristylis vahlii belong to?
Fimbristylis vahlii is in the Cyperaceae family, genus Fimbristylis.
What habitat does Fimbristylis vahlii grow in?
Fimbristylis vahlii grows in Moist to wet soil, alluvial or mineralized banks, shores, fluctuating pond, lake margins.
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.