Isolepis carinata

Keeled bulrush

Family: Cyperaceae · Type: annual · Native

Keeled bulrush is a California native annual found in northern coastal, central coastal, and San Francisco Bay Area bioregions in grasslands, rock barrens, and open woodland at elevations below 800 meters. Flowering in spring, this plant produces small, delicate flowers in compact clusters with subtle brownish-green tones. Growing with slender stems 1 to 25 centimeters tall, it forms a single thin leaf and delicate inflorescence. Its single leaf and flower bracts are distinctive, with bracts often clasping and shedding fruit that is tiny and precisely 1 to 1.5 millimeters wide. The fruit is three-sided with slightly concave sides, creating a unique geometric profile in its miniature grassland habitats.

Habitat: Often drying wet places in grassland, rock barrens, open woodland

Bloom period: Spring

Elevation: < 800 m

Bioregions: NCo, NCoRO, CCo, SnFrB

California counties: Orange, Marin, Monterey, San Luis Obispo, Sonoma, San Diego, Ventura, Mendocino, Butte, Santa Cruz, San Mateo, Humboldt, Napa

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.