Potamogeton crispus
Crisp-leaved pondweed
Family: Potamogetonaceae · Type: annual · Not Native
Conservation status: Cal-IPC Yes
Crisp-leaved pondweed is a naturalized aquatic annual found in shallow water ecosystems across California, including the Klamath Ranges, North Coast Ranges, Central California Valley, coastal areas, Channel Islands, and desert regions at elevations up to 2,100 meters. Flowering from July to September, this plant produces small, inconspicuous greenish flowers in compact underwater inflorescences. Growing with slender, branching stems up to 90 centimeters long that are slightly compressed, it spreads through hard winter buds in aquatic environments. Its submersed leaves are distinctively wavy and serrated, measuring 4 to 8 centimeters long and 0.5 to 0.8 centimeters wide, with rounded tips and 3 to 5 subtle veins. The fruit is 4 to 6 millimeters long with slightly concave to convex sides and a short 2 to 3 millimeter beak.
Habitat: Uncommon. Shallow water, ponds, streams
Bloom period: Jul-Sep
Elevation: < 2100 m
Bioregions: KR, NCoR, CaR, s SN, n SNH, GV, CCo, SnFrB, SCo, ChI, SnGb, SnBr, PR, D
California counties: Riverside, Orange, Los Angeles, Fresno, San Bernardino, Stanislaus, Kern, Merced, San Joaquin, Alameda, Butte, Tehama, Inyo, Shasta, Sonoma, Imperial, Contra Costa, Madera, Marin, Mendocino, San Francisco, Santa Barbara, Siskiyou, Tuolumne, Solano, Lake, Sutter, Glenn, Napa, Mariposa, Plumas, Humboldt, San Mateo, San Diego, Santa Clara, El Dorado, Sacramento, Monterey, Lassen, Mono
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.