Callitriche palustris

Vernal water-starwort

Family: Plantaginaceae · Type: perennial · Native

Vernal water-starwort is a California native perennial found in the California Floristic Province and Great Basin in submerged habitats, with populations occurring at elevations up to 4,000 meters. Flowering from May to August, this aquatic plant produces tiny, inconspicuous flowers in delicate rosettes that float on water surfaces or become stranded at lake and stream edges. Growing with thin, adaptable stems, it forms distinctive floating and submersed leaf structures that change shape depending on its aquatic environment. Its leaves are uniquely variable, with submersed leaves appearing linear-oblong and floating leaves developing a spoon-shaped form that gradually narrows to a short petiole, typically 3 to 4.5 millimeters long. In terrestrial or emergent conditions, the plant produces compact leaves about 1 millimeter wide, demonstrating remarkable morphological flexibility across different water habitats.

Habitat: Submerged, with floating rosettes or becoming stranded at edge of lake, pools, or streams

Bloom period: May-Aug

Elevation: < 4000 m

Bioregions: CA-FP, GB

California counties: Shasta, Fresno, Modoc, Sonoma, Butte, Siskiyou, Lassen, San Bernardino, Mendocino, San Diego, Humboldt, Mono, Santa Cruz, Sierra, Placer, El Dorado, Alpine, Santa Barbara, Inyo, Tuolumne

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