Japanese Knotweed

Fallopia japonica Ronse Decraene is an ornamental, nevertheless a weed in Chile Reynoutria japonica Houtt. it can be easily distinguish from F sachalinensis taking into account the base of leaves truncate vs cordate

Checklist as viewed on GBIF-Database
Fallopia japonica (bas.:Reynoutria)
 * Polygonum cuspidatum Sieb. et Zucc.

Tanja Schuster et al. would be recognizing two genera Fallopia and Reynoutria PHYLOGENETIC RELATIONSHIPS OF MUEHLENBECKIA, FALLOPIA, AND REYNOUTRIA (POLYGONACEAE) INVESTIGATED WITH CHLOROPLAST AND NUCLEAR SEQUENCE DATA