Carex mertensii
Mertens' sedge
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Family: Cyperaceae · Type: Grass · Native
Carex mertensii (Mertens' sedge) is a native California grass in the Cyperaceae family, recognized by large spikelets and wide flat perigynia.
Mertens' sedge is a California native perennial found in the Klamath Ranges in wet open areas at elevations around 1,500 meters. Flowering with delicate spikelets arranged in clusters up to 2 centimeters long, this sedge produces inflorescences with pistillate flower bracts in dark brown to dark purple tones. Growing in dense tufts with stems 30 to 120 centimeters tall, it forms thick clumps in moist habitats. Its leaves are relatively narrow, with blade width ranging from 4 to 7 millimeters, and the lowest leaves have distinctive vestigial staminate flowers. The fruit is small and compact, with a green perigynia subtly dotted with purple and a short beak.
Identification and appearance
Key characters: 76 sympatric species; large spikelets and wide flat perigynia are diagnostic
Habitat and range
Habitat: Wet open areas
Elevation: +- 1500 m.
California counties: Siskiyou, Trinity, Del Norte
Outside California: to Alaska, Montana
How to tell it apart
vs Juncus: Carex stems are triangular when rolled; Juncus stems are round and often hollow with partitions inside.; vs Cyperus: Carex has seeds in individual flasks; Cyperus has umbrella-like flower clusters with flattened ribbon-like spikes.; vs Plantago: Carex has triangular stems and brown/green spikelets; Plantago has round flower stalks and white/brown spike flowers.; vs Eleocharis: Carex has leaves along the stem; Eleocharis is nearly leafless with just one spikelet per stem.; vs Schoenoplectus: Carex has leafy stems and flask-enclosed seeds; Schoenoplectus has leafless round stems with exposed seeds.
Frequently asked questions
Is Carex mertensii native to California?
Yes. Carex mertensii is native to California (recorded as native).
Where in California does Carex mertensii grow?
Carex mertensii occurs in Siskiyou, Trinity, Del Norte, at elevations of +- 1500 m..
What plant family does Carex mertensii belong to?
Carex mertensii is in the Cyperaceae family, genus Carex.
What habitat does Carex mertensii grow in?
Carex mertensii grows in Wet open areas.
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.