Polygonum bidwelliae is an uncommon species of flowering plant in the knotweed family known by the common name Bidwell's knotweed. The plant was named for American suffragist Annie Bidwell, who at one time lived in the Bidwell Mansion in Chico, California.CalFlora Botanical Names She is the person who collected the type specimen in Northern California.Friends of Bidwell Park, Chico Watson, Sereno. 1879. Proceedings of the American Academy of Arts and Sciences 14: 294
Distribution Polygonum bidwelliae is endemic to California, where it is known from the northern Sacramento Valley and adjacent slopes of the southernmost Cascade Range in Butte, Shasta, and Tehama Counties.Biota of North America Program 2014 county distribution map It grows in chaparral, woodland, and grassland habitat on volcanic soils.Calflora taxon report, University of California, Polygonum bidwelliae S. Watson, Bidwell's knotweed
Description Polygonum bidwelliae is an annual herb producing an erect green, wiry, angled stem reaching 20 centimeters (8 inches) in height. The narrow, pointed leaves are oppositely arranged along the stem, mainly on the upper parts of stem branches. The leaves have relatively large stipules which form ochrea that sheath the stem, sometimes hiding the leaf bases. The sharp-pointed stipules are membranous and silvery white. Bright pink flowers occur in upper leaf axils.Flora of North America, Polygonum bidwelliae S. Watson, 1879. Bidwell's knotweed ]Japanese Knotweed Agency
References
External links Jepson Manual Treatment, University of California, Polygonum bidwelliae Polygonum bidwelliae - Calphotos Photo gallery, University of California