Calflora, a 501c3 non-profit
Distribution by County   4279    
Hydrilla verticillata  (L. f.) Royle
Hydrilla,   Waterthyme
Hydrilla verticillata is a perennial herb that is not native to California.
Cal-IPC rating: high
Record Count by County

Calaveras: 16 Mariposa: 14 San Bernardino: 1 Tulare: 5
Fresno: 2 Mendocino: 1 San Diego: 5 Yuba: 19
Imperial: 32 Nevada: 1 San Joaquin: 1
Lake: 46 Orange: 1 Shasta: 23
Madera: 13 Placer: 2 Tehama: 1

Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria. [web application]. 2024. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 11/21/2024).