Eleocharis acicularis
Needle spikerush
no rights reserved · CC0
Family: Cyperaceae · Type: Grass · Native
Eleocharis acicularis (Needle spikerush) is a native California grass in the Cyperaceae family.
Needle spikerush is a native perennial found in wetland and aquatic habitats, often forming dense mats in shallow water environments. Typically flowering throughout the summer months, this small rush produces minute flowers in compact spikes typically 2 to 8 millimeters long. Growing with slender, thread-like stems 1 to 60 centimeters tall, it can form delicate, spreading ground cover with weak rhizomes less than half a millimeter in diameter. Its stems are distinctively thin, measuring just 0.2 to 0.5 millimeters wide, and often have three to twelve subtle angles or ridges along their length. The fruit is tiny, approximately 1 millimeter long, with eight to twelve longitudinal ridges and a distinctive white to pale coloration.
Identification and appearance
Key characters: Geographically isolated - no sympatric species
Habitat and range
California counties: Kern, Riverside, San Diego, Sonoma, Inyo, Tulare, Fresno, San Bernardino, Lassen, Orange, Santa Barbara, Modoc, Lake, Los Angeles, Madera, Imperial, Amador, Plumas, Mendocino, Nevada, Mariposa, Marin, Humboldt, San Luis Obispo, San Mateo, El Dorado, Santa Clara, Monterey, Tuolumne, Butte, Glenn, Ventura, Mono, Stanislaus, Tehama, Placer, Siskiyou, Contra Costa, Shasta, Alpine, Merced, Calaveras, Sierra, Sacramento, Trinity, Sutter, San Joaquin, San Francisco, Santa Cruz, Yuba, San Benito
How to tell it apart
vs Carex: Eleocharis has single spikelet with no bracts below, Carex has leafy bracts and multiple spikes.; vs Isolepis: Eleocharis has no bracts below spikelet, Isolepis has conspicuous leaf-like bracts extending beyond flowers.; vs Schoenoplectus: Eleocharis has single terminal spikelet, Schoenoplectus has multiple spikelets in clusters.; vs Juncus: Eleocharis spikelets are flattened oval, Juncus flowers are round with visible petals in clusters.; vs Equisetum: Eleocharis has grass-like stems with flower spikelets, Equisetum has jointed hollow stems with cone-like structures.
Frequently asked questions
Is Eleocharis acicularis native to California?
Yes. Eleocharis acicularis is native to California (recorded as native).
Where in California does Eleocharis acicularis grow?
Eleocharis acicularis occurs in Kern, Riverside, San Diego, Sonoma, Inyo, Tulare, Fresno, San Bernardino and other counties.
What plant family does Eleocharis acicularis belong to?
Eleocharis acicularis is in the Cyperaceae family, genus Eleocharis.
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.