Cyperus flavicomus
Whiteedge flatsedge
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Family: Cyperaceae · Type: Grass · Not Native
Cyperus flavicomus (Whiteedge flatsedge) is a non-native California grass in the Cyperaceae family, recognized by large size, spreading bracts with lateral veins, and large fruits distinctive.
Whiteedge flatsedge is a naturalized annual found in the Sacramento Valley, specifically Butte County, in marshy and damp places at approximately 100 meters elevation. Flowering from August to October, this plant produces light brown to deep red flowers in compact spikes 8 to 22 millimeters wide, with spikelets 7 to 30 millimeters long. Growing 30 to 75 centimeters tall with 1 to 3 stems, it forms an open, branching inflorescence with 3 to 7 long bracts extending 5 to 35 centimeters. Its flowers have spreading bracts 1.7 to 2.3 millimeters long with distinctive lateral veins and 2 stigmas. The fruit is a small, black to dark red-brown, two-sided obovoid seed approximately 1.2 to 1.6 millimeters long.
Identification and appearance
Key characters: 13 sympatric species; large size, spreading bracts with lateral veins, and large fruits distinctive
Habitat and range
Habitat: Marshy, damp places
Elevation: +- 100 m.
Outside California: to eastern United States, Mexico, South America, Old World
Bloom period
Cyperus flavicomus blooms Aug-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 flavicomus native to California?
No. Cyperus flavicomus is not native to California (recorded as not native).
When does Cyperus flavicomus bloom?
Cyperus flavicomus blooms Aug-Oct.
What plant family does Cyperus flavicomus belong to?
Cyperus flavicomus is in the Cyperaceae family, genus Cyperus.
What habitat does Cyperus flavicomus grow in?
Cyperus flavicomus grows in Marshy, damp places.
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.