Polygonum douglasii ssp. johnstonii Calflora

Distribution by County 6751

Polygonum douglasii Greene ssp. johnstonii (Munz) J. C. Hickman

(not an active name)

Johnston's knotweed, Knotweed

Polygonum douglasii ssp. johnstonii is an annual herb that is native to California, and also found elsewhere in western North America.

also called Polygonum sawatchense ssp. sawatchense

Record Count by County


Alpine: 5	Kern: 2	Placer: 7	Siskiyou: 7
Butte: 2	Lassen: 18	Plumas: 24	Tehama: 2
Colusa: 1	Madera: 1	Riverside: 1	Trinity: 3
El Dorado: 3	Mariposa: 3	San Bernardino: 21	Tulare: 11
Fresno: 2	Modoc: 7	San Diego: 9	Tuolumne: 5
Humboldt: 6	Mono: 29	Shasta: 6	Ventura: 5
Inyo: 13	Nevada: 17	Sierra: 7

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: 12/03/2024).