Isoetes occidentalis

Western quillwort

Family: Isoetaceae · Type: perennial · Native

Western quillwort is a California native aquatic perennial found in the Klamath Ranges and Sierra Nevada Highlands in persistent lakes and high-elevation pools above 1,500 meters. This distinctive underwater plant produces no visible flowers, instead reproducing through specialized spores with unique characteristics. Growing with evergreen leaves less than 20 centimeters long, the plant features rigid, brittle, dark green leaves that taper to a point and have a distinctive brown-white base. Its leaves emerge completely underwater, with a remarkable structural complexity including male spores around 0.035 to 0.045 millimeters and larger female spores approximately 0.5 to 0.7 millimeters with intricate ridged and tubercled surfaces. The plant's genetic makeup is notably complex, with a chromosome count of 2n=66, reflecting its sophisticated evolutionary adaptation to persistent aquatic environments.

Habitat: Persistent lakes, pools

Elevation: > 1500 m

Bioregions: KR, SNH

California counties: Sierra, Tuolumne, Siskiyou, Tulare, El Dorado, Fresno, Inyo, Nevada, Madera, Amador, Trinity, Plumas, Mariposa, Mono

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