Cyperus rotundus
Purple nutsedge, Purple Nutsedge
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Family: Cyperaceae · Type: Grass · Not Native
Cyperus rotundus (Purple nutsedge) is a non-native California grass in the Cyperaceae family, recognized by purple bracts with many veins and seldom-maturing fruits.
Purple nutsedge is a naturalized perennial herb found in the Central Valley, southern California Coast, and desert southern regions in disturbed soils and cropland at elevations below 250 meters. Flowering from July to November, this plant produces purple to red-brown flowers in compact spikes with distinctive ovate flower bracts. Growing with underground stolons that produce small tubers, it forms clumps 10 to 40 centimeters tall with spreading ray-like inflorescences. Its stems have 2 to 5 long bracts and develop complex clustered spikes with 3 to 12 spikelets arranged in open, elliptic formations. The fruit is small, elliptic, and black, though it rarely reaches full maturity.
Identification and appearance
Key characters: 17 sympatric species; purple bracts with many veins and seldom-maturing fruits help distinguish
Habitat and range
Habitat: Disturbed soils, cropland
Elevation: < 250 m
Outside California: tropics, warm temperate, native to Eurasia
Bloom period
Cyperus rotundus blooms Jul-Nov.
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 rotundus native to California?
No. Cyperus rotundus is not native to California (recorded as not native).
When does Cyperus rotundus bloom?
Cyperus rotundus blooms Jul-Nov.
What plant family does Cyperus rotundus belong to?
Cyperus rotundus is in the Cyperaceae family, genus Cyperus.
What habitat does Cyperus rotundus grow in?
Cyperus rotundus grows in Disturbed soils, cropland.
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.