*Reynoutria japonica Houttuyn var. japonica . Japanese Knotweed, Japanese Bamboo, Japanese Buckwheat. Phen: May-Oct; Aug-Oct. Hab: Roadsides, disturbed areas, river banks and sandbars, often forming dense thickets. Dist: Native of e. Asia.

Origin/Endemic status: E. and se. Asia

Taxonomy Comments: Three varieties are endemic in Japan and Korea; they are not known to be introduced in our region (Freeman & Hinds 2005; Desjardins et al. 2023).

Synonymy: = Desjardins et al (2023); = Fallopia japonica (Houtt.) Ronse Decr. var. japonica – Ar, FNA5, NE; < Fallopia japonica (Houtt.) Ronse Decr. – Mi, Pa, Tn, Ronse De Craene & Akeroyd (1988); < Pleuropterus zuccarinii Small – S; < Polygonum cuspidatum Siebold & Zucc. – C, F, GrPl, K1, RAB, Tat, W, WV, Horton (1972), Mitchell & Dean (1978); < Reynoutria japonica Houtt. – Fl4, Il, K3, K4, NY, Va, Lin et al (2013)

Show in key(s)

Show parent genus

Wetland Indicator Status:

• Atlantic and Gulf Coastal Plain: UPL (name change)
• Eastern Mountains and Piedmont: FACU (name change)
• Great Plains: FACU (name change)
• Midwest: FACU (name change)
• Northcentral & Northeast: FACU (name change)