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Taxon  Report  
Fallopia ×bohemica  (Chrtek & Chrtkova) J. P. Bailey
Bohemian knotweed
Fallopia ×bohemica is a perennial herb that is not native to California.
There is a high risk of this plant becoming invasive in California according to Cal-IPC.
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Observation Search
~2 records in California
redone or more occurrences
within a 7.5-minute quadrangle
Genus: Fallopia
Family: Polygonaceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Name Status:

Alternate Names:
CalfloraFallopia bohemica
inatReynoutria Xbohemica
usdaPolygonum Xbohemicum
Information about  Fallopia ×bohemica from other sources
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Photos on iNaturalist

International Plants Names Index

Search efloras.org (Flora of North America)

Cal-IPC Profile rating: watch (high risk)

Consortium of California Herbaria 2

[Wikipedia] Japan native, Description, Distribution, Manangement: Bohemian knotweed is a nothospecies that is a cross between Japanese knotweed and giant knotweed. It has been documented as occurring in the wild in Japan.[1] The scientific name is accepted to be Reynoutria × bohemica,[2] but it may also be referred to as Fallopia × bohemica and Polygonum × bohemicum.[3] The species was first described by Jind?ich Chrtek [es] and Anna Chrtková [cy] in the Czech Republic in 1983.[3] Description The species is an herbaceous perennial that can spread through seeds and rhizomes. It can exceed 3.5 meters in height. Leaves are larger than those of Japanese knotweed, and leaf bases are less squared. White flowers typically open in August.[3] The species can be verified by the hairs along the mid-vein on the undersides of leaves, which are of different shape and texture than those found on either parent species.[4] Distribution Bohemian knotweed is typically found in riparian areas and waste places.[3] From the late 1800s, knotweeds have been introduced to new areas as an ornamental garden plant.[1] The species has a worldwide distribution. It is considered by some as being a native hybrid of Japan.[1] In Europe, it has been reported from the British Isles, Germany, France, northern Italy, Serbia, Bulgaria, Belgium, the Czech Republic, Slovakia, Romania, Ukraine, Scandinavia, and Switzerland. It is widespread in North America, and it has been discovered in Chile. It has also been found in Australia.[3] Management In some areas, Bohemian knotweed is classified as an invasive species and a noxious weed. It is illegal to transport and sell in multiple US states, including Minnesota,[1] Washington,[5] and Wisconsin.[6] (contributed by Mary Ann Machi)


Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2024. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 04/22/2024).