Persicaria bistorta or Japanese knotweed?

[SouthPotty]

I bought a lovely plant described by the nursery as Persicaria bistorta superba. But when I googled it's pictures, the pictures looked nothing like the actual plant. So I used one of those plant recognition apps and it came back as Japanese knotweed 🫢
However, when I googled pictures of actual Japanese knotweed, the leaves looked different to the potted plant so I'm not sure what it might be.
Can anyone confirm that it's a Persicaria, not knotweed, and whether it's superba or some other variety?

I think you're right to be suspicious - it doesn't look anything like Persicaria bistorta superba, and does look to me a lot like knotweed. I don't know if it could be a different type of polygonatum, but I'm pretty sure it's not what it was sold to you as so I think you should definitely take it back and get your money back (and probably go elsewhere in future!)

Polygonum, not Polygonatum. Polygonatum is Solomon’s Seal.

Yes, not Persicaria bistorta, and it does look more like a Polygonum.

It's not Japanese knotweed but is closely related, I think!

en.m.wikipedia.org/wiki/Reynoutria

Thank you all, it's not looking good, is it.
I actually got it a couple of months back but left it in the pot, waiting for a space to clear. I've got other persicarias and they all look different so wasn't that concerned.
I'll keep it for a while and wait for it to start flowering as it seems that knotweed has quite distinctive flowers.

JK has got serrated edges to the leaves - the leaves in your pics looks smooth.

Are you sure of that? My experience of JK is with what I would call smooth edges

Himalayan Balsam has serrated edges

JK has quite soft bright green heart shaped leaves - I would say those on your plant are leathery and smaller than JK

Thank you again. Yes, the leaves are bright green, leathery and quite shiny. JK seems to have large papery leaves but young plants look quite similar to my plant, that's why I'm worried.

It looks like Houttuynia to me. It has small white flowers and spreads. It is useful under hedges and in dry areas, but it spreads like mad. I really regret planting it!
Not a cheap plant either!

Not sure. Leaf bases don’t look cordate (heart shaped) enough to me, and veins don’t look right. But flowering will confirm

I wouldn’t let it out into the ground, and I’d clip off any roots that make their way out of the pot. If it turns out to be JK, look up how to dispose of it. You may have to burn it on site or take it to a hazardous waste disposal site. Don’t put it in your green bin or your landfill bin.

If it turns out to be JK, look up how to dispose of it. You may have to burn it on site or take it to a hazardous waste disposal site. Don’t put it in your green bin or your landfill bin.

If it is JK I'd definitely be taking it back to the nursery for them to deal with and get a refund.
Tbh even if it's not, I'd still do that as it's not what it was sold as. Does it still have a label, OP?

I’m posting a couple of photos of my Houttuynia, before I have another go at reducing it. There are several varieties, some with a pink tinge. It does have a scent, so rubbing the leaves might give you a clue.

Hmmm, i don't think it's hoyttunia, I've got one (or a million now) in my garden - the variegated colourful one. I googled other varieties and the leaves are not it although there's that red tinged variety that looks slightly like my plant. I think the flowers will be the decisive factor. I'll update when I've solved the mystery 😊