Eleocharis decumbens
Decumbent spikerush
Family: Cyperaceae · Type: Grass · Native
Eleocharis decumbens (Decumbent spikerush) is a native California grass in the Cyperaceae family, recognized by 20 co-occurring species; thick exposed rhizomes and long bristles.
Decumbent spikerush is a California native perennial found in the Klamath Ranges, northern Coast Ranges, high Cascade Range, and Sierra Nevada in fresh wet meadows, fens, seeps, and lake shores at elevations of 500 to 2,500 meters. Flowering during summer, this plant produces small spikelets 3 to 8 millimeters long with tightly clustered green to brown flowers. Growing with slender stems 10 to 50 centimeters tall and a tough rhizome 3 to 5 millimeters in diameter, it forms dense clumps in moist habitats. Its leaf sheaths are firm and persistent, with tips that are slightly truncate to obtuse. The fruit is a small three-sided structure about 1 to 1.3 millimeters long, accompanied by six delicate perianth bristles that are typically as long as or longer than the seed's base.
Identification and appearance
Key characters: 20 co-occurring species; thick exposed rhizomes and long bristles are diagnostic
Habitat and range
Habitat: Fresh wet meadows, fens, seeps, lake shores
Elevation: 500-2500 m
California counties: Butte, Siskiyou, El Dorado, Mariposa, Trinity, Tulare, Inyo, Calaveras, Fresno, Sierra, Plumas, Nevada, Madera, Tuolumne
Outside California: southern Oregon
Bloom period
Eleocharis decumbens blooms Summer.
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 decumbens native to California?
Yes. Eleocharis decumbens is native to California (recorded as native).
When does Eleocharis decumbens bloom?
Eleocharis decumbens blooms Summer.
Where in California does Eleocharis decumbens grow?
Eleocharis decumbens occurs in Butte, Siskiyou, El Dorado, Mariposa, Trinity, Tulare, Inyo, Calaveras and other counties, at elevations of 500-2500 m.
What plant family does Eleocharis decumbens belong to?
Eleocharis decumbens is in the Cyperaceae family, genus Eleocharis.
What habitat does Eleocharis decumbens grow in?
Eleocharis decumbens grows in Fresh wet meadows, fens, seeps, lake shores.
Related species
Other California species in the same genus, family, or bioregion.
- Eleocharis engelmannii — Engelmann's spikerush
- Eleocharis engelmannii var. detonsa — Engelmann's spikerush
- Eleocharis engelmannii var. engelmannii — Engelmann's spikerush
- Eleocharis flavescens var. flavescens — Yellow spikerush
- Eleocharis geniculata — Bent spikerush
- Eleocharis macrostachya — Common spikerush
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.