JW has large, unlobed, heart-shaped leaves and hollow cane-like stems

And does produce an aggressively creeping rootstock instead of a tight clump of growth.

As an aside the common nuisance kind in some areas - including much of the Pacific Northwest and Great Britain - is Bohemian knot-weed rather than Japanese. It is an intermediate hybrid resulting from the crossing of Japanese and giant knot-weeds, with the hybrid plants often being male. So that there is not a problem with these male plants reseeding. Just covering large spaces with their vegetative growth if they are not destroyed. I have seen uncontrolled patches in my area occupying square footage the size of entire building lots - and bigger. If still nobody has done anything about it there is an infested bottom-land in the bend of a river in a National Forest east of here that may be something on the order of an acre in extent.

floral_uk - thank you for your insight!!!! That makes me feel a whoooole lot better since all I’ve been doing in the last couple of hours is researching the endless headaches that knotweed can cause!

embothrium - thank for the info. So do you agree that the plant in the pics I posted is NOT Japanese knotweed?

As floral already stated, the plant in question is a peony. It is not any type of knotweed!!

Yay!!!! Now I can sleep tonight. :)

Thank you both!!

Edit: thank you ALL!

If it doesn't flower, it might be planted in too shade a spot or too deeply.

" a case of Goutweed" LOL!