Cyperus eragrostis
Tall cyperus
Photo by Chez Brungraber
Family: Cyperaceae · Type: Grass · Native
Cyperus eragrostis (Tall cyperus) is a native California grass in the Cyperaceae family, recognized by large size, spherical heads, and netted black fruits diagnostic.
Tall cyperus is a California native perennial found in the California Floristic Province in vernal pools and streambanks at elevations below 700 meters. Flowering from May to November, this plant produces beige flower bracts 2 to 2.3 millimeters long in spheric heads 1.5 to 4 centimeters wide. Growing with stems 10 to 90 centimeters tall, the plant develops complex inflorescences with 4 to 8 bracts and up to 10 rays extending 20 to 100 millimeters. Its flower clusters contain 20 to 70 oblong spikelets, each 5 to 20 millimeters long with distinctive three-part stigmas. The small fruit is fine-netted, black or dark brown, approximately 1.2 to 1.4 millimeters long with a beaked tip.
Identification and appearance
Key characters: 19 sympatric species; large size, spherical heads, and netted black fruits diagnostic
Habitat and range
Habitat: Vernal pools, streambanks
Elevation: < 700 m
California counties: Humboldt, Sutter, Butte, San Diego, San Bernardino, Riverside, Los Angeles, Kern, Orange, Tehama, Yuba, Alameda, Amador, Calaveras, Contra Costa, Fresno, Glenn, Lake, Madera, Marin, Mariposa, Mendocino, Merced, Monterey, Napa, Placer, Sacramento, San Francisco, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, Shasta, Sonoma, Stanislaus, Tulare, Tuolumne, Ventura, Yolo, Colusa, San Joaquin, El Dorado, Nevada, Solano, Del Norte, Plumas, Trinity, Kings, Siskiyou, Imperial, San Benito
Outside California: to southern British Columbia, temperate South America
Bloom period
Cyperus eragrostis blooms May-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 eragrostis native to California?
Yes. Cyperus eragrostis is native to California (recorded as native).
When does Cyperus eragrostis bloom?
Cyperus eragrostis blooms May-Nov.
Where in California does Cyperus eragrostis grow?
Cyperus eragrostis occurs in Humboldt, Sutter, Butte, San Diego, San Bernardino, Riverside, Los Angeles, Kern and other counties, at elevations of < 700 m.
What plant family does Cyperus eragrostis belong to?
Cyperus eragrostis is in the Cyperaceae family, genus Cyperus.
What habitat does Cyperus eragrostis grow in?
Cyperus eragrostis grows in Vernal pools, streambanks.
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.