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Bidwell's Knotweed
Polygonum bidwelliae
About Bidwell's Knotweed (Polygonum bidwelliae) 0 Nurseries Carry This Plant 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. She is the person who collected the type specimen in Northern California. 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. It grows in chaparral, woodland, and grassland habitat on volcanic soils. 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.
Plant Description
Plant Type
Plant Type
Annual herb

0.8 - 7.9 in tall

Flower Color
Flower Color
Pink, White

Wildlife Supported

Landscaping Information
Natural Setting
Annual Precipitation: 21.7" - 62.7", Summer Precipitation: 0.59" - 1.98", Coldest Month: 36.1" - 53.0", Hottest Month: 63.6" - 75.8", Humidity: 1.78" - 25.71", Elevation: 198" - 4040"

Sources include: Wikipedia. All text shown in the "About" section of these pages is available under the Creative Commons Attribution-ShareAlike License. Plant observation data provided by the participants of the California Consortia of Herbaria, Sunset information provided by Jepson Flora Project. Propogation from seed information provided by the Santa Barbara Botanical Garden from "Seed Propagation of Native California Plants" by Dara E. Emery. Sources of plant photos include CalPhotos, Wikimedia Commons, and independent plant photographers who have agreed to share their images with Calscape. Other general sources of information include Calflora, CNPS Manual of Vegetation Online, Jepson Flora Project, Las Pilitas, Theodore Payne, Tree of Life, The Xerces Society, and information provided by CNPS volunteer editors, with special thanks to Don Rideout. Climate data used in creation of plant range maps is from PRISM Climate Group, Oregon State University, using 30 year (1981-2010) annual "normals" at an 800 meter spatial resolution.

Links:   Jepson eFlora Taxon Page  CalPhotos  Wikipedia  Calflora

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