Checklist » Asteraceae » Petasites japonicus var. japonicus
Last updated 5/6/2004 by Peter F. Zika.
Petasites japonicus (Siebold & Zucc.) Maxim. var. japonicus
Japanese sweet coltsfoot

Origin: Introduced from eastern Asia

selected vouchers: WTU

Notes: Recently collected in Thurston Co. Petasites hybridus was reported for Washington by Kartesz, based on one of the 1998 Petasites papers by Cherniawsky and Bayer (1998a, b, c). However, none of those papers mention Petasites hybridus in Washington (they also fail to mention any adventive taxa in North America). A similar report of Petasites hybridus from British Columbia is rejected by Douglas et al. (1998, p. 408), with the suggestion that the reports were based on collections of introduced Petasites japonicus.

References:

» Cherniawsky, D. M. and R. J. Bayer. 1998a. Systematics of North American Petasites (Asteraceae: Senecioneae). I. Morphometric analysis. Canadian Journal of Botany 76: 23-36.
» Cherniawsky, D. M. and R. J. Bayer. 1998b. Systematics of North American Petasites (Asteraceae: Senecioneae). II. Isozyme analysis and population genetic structure. Canadian Journal of Botany 76: 1476-1487.
» Cherniawsky, D. M. and R. J. Bayer. 1998c. Systematics of North American Petasites (Asteraceae: Senecioneae). III. A taxonomic revision. Canadian Journal of Botany 76: 2061-2075.
» IFBC1 = Douglas, G. W., G. B. Straley, D. V. Meidinger, and J. Pojar (eds). 1998. Illustrated Flora of British Columbia, Volume 1: Gymnosperms and Dicotyledons (Aceraceae Through Asteraceae). B.C. Ministry of Environment, Lands & Parks and B.C. Ministry of Forests. Victoria. 436 p.
Synonyms & Misapplied Names:
(none)