Cyperus fuscus
Brown flatsedge
(c) Yuri Sofronov, some rights reserved (CC BY) · licence
Family: Cyperaceae · Type: Grass · Not Native
Cyperus fuscus (Brown flatsedge) is a non-native California grass in the Cyperaceae family, recognized by multiple stems, round mucronate bracts, and 3-veined bracts diagnostic.
Brown flatsedge is a naturalized annual sedge found in the Central Valley in damp disturbed soil, receding shorelines, and puddles at elevations below 50 meters. Flowering from July to October, this plant produces yellow to purple-brown flowers in small spherical heads with 3 to 15 narrow-elliptic spikelets 3 to 7 millimeters long. Growing with slender stems 2 to 30 centimeters tall, it forms delicate, open inflorescences with 2 to 3 spreading rays. Its flower bracts are round, approximately 1 millimeter long, with three prominent midveins and no lateral veins. The tiny ellipsoid fruit is light brown, 0.7 to 1 millimeter long, with a wedge-shaped base and acute tip.
Identification and appearance
Key characters: 13 sympatric species; multiple stems, round mucronate bracts, and 3-veined bracts diagnostic
Habitat and range
Habitat: Damp disturbed soil, receding shorelines, puddles
Elevation: < 50 m
California counties: Glenn, Butte, Calaveras, San Joaquin, Sonoma, Alameda, Tehama, Monterey, Sacramento
Outside California: to eastern North America, native to temperate Eurasia
Bloom period
Cyperus fuscus blooms Jul-Oct.
How to tell it apart
vs Carex: Cyperus has umbrella clusters with flat spikes; Carex has brown/green spikelets with seeds in individual flasks.; vs Scirpus: Cyperus has flattened ribbon-like spikes; Scirpus has rounded, cylindrical spikelets.; vs Juncus: Cyperus has triangular stems and flat flower spikes; Juncus has round stems and individual flowers.; vs Sticherus: Cyperus is a sedge with triangular stem; Sticherus is a fern with fronds.; vs Eleusine: Cyperus has triangular stems; Eleusine is a grass with round stems and obvious grass flowers.
Frequently asked questions
Is Cyperus fuscus native to California?
No. Cyperus fuscus is not native to California (recorded as not native).
When does Cyperus fuscus bloom?
Cyperus fuscus blooms Jul-Oct.
Where in California does Cyperus fuscus grow?
Cyperus fuscus occurs in Glenn, Butte, Calaveras, San Joaquin, Sonoma, Alameda, Tehama, Monterey and other counties, at elevations of < 50 m.
What plant family does Cyperus fuscus belong to?
Cyperus fuscus is in the Cyperaceae family, genus Cyperus.
What habitat does Cyperus fuscus grow in?
Cyperus fuscus grows in Damp disturbed soil, receding shorelines, puddles.
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.