Fallopia japonica (Houtt.) Ronse Decr.
Common Name: JAPANESE KNOTWEED, MEXICAN BAMBOO
Synonym: Polygonum cuspidatum
Coefficient of Conservatism: *
Coefficient of Wetness: 3
Wetness Index: FACU
Physiognomy: Ad P-Forb

Fallopia japonica A. A. Reznicek

Polygonum cuspidatum of Michigan Flora.

A native of Japan, planted as an ornamental and found as an escape at gravel pits, filled ground, roadsides, dumps, and gullies. First collected in 1919 in Wayne Co.

Both this species and F. sachalinensis grow from sturdy rhizomes and are difficult to eradicate once established. They form dense thickets as tall as 2 m or more. Whenever there is a report of “bamboo” in Michigan, it is likely to be based on one of these stout species, which have hollow internodes (true bamboos are grasses and very rarely known to escape in Michigan; see Phyllostachys). Some specimens from Alcona, Ingham, and Newaygo Cos. are apparently the hybrid F. ×bohemica (Chrtek & Chrtková) J. P. Bailey; see Zika & Jacobson (2003) for more information.

Locations

Alcona County
Alpena County
Baraga County
Benzie County
Berrien County
Chippewa County
Clinton County
Eaton County
Emmet County
Gogebic County
Hillsdale County
Houghton County
Ingham County
Iron County
Kalamazoo County
Kent County
Lapeer County
Leelanau County
Lenawee County
Marquette County
Mecosta County
Muskegon County
Newaygo County
Oakland County
Ottawa County
Presque Isle County
Van Buren County
Washtenaw County
Wayne County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 18, 2017. http://www.michiganflora.net/species.aspx?id=2276.