Is this Japanese knotweed

[Kariha]

This plant appeared in my garden this summer and I don't remember planting it. I thought it was quite pretty, but now I'm worried it may be Japanese knotweed. Can anyone tell me what they think it is? Hopefully it's not the dreaded weed!! It is the one with the deep pink spiked flowers and the bright green leaves.
Thanks in advance. I am new to the forum.

 

[Sheal]

Welcome Kariha.

Having looked at your images several times I don't think it's Japanese Knotweed although the leaves would suggest it is. Knotweed has white flowers and a distinctive zigzag in the stems as below...

There is a smaller form of Knotweed that has pink flowers but they don't resemble the flowers in your images. Is it possible for you to take a picture of any new stems growing from the soil, and a better shot of the flower please? It would be wise to check whether the plant is growing in neighbouring gardens.

 

[Kariha]

Welcome Kariha.

Having looked at your images several times I don't think it's Japanese Knotweed although the leaves would suggest it is. Knotweed has white flowers and a distinctive zigzag in the stems as below...

View attachment 104999

There is a smaller form of Knotweed that has pink flowers but they don't resemble the flowers in your images. Is it possible for you to take a picture of any new stems growing from the soil, and a better shot of the flower please? It would be wise to check whether the plant is growing in neighbouring gardens.

Hi, I think I have identified it as a type of Persicaria amplexicoulis or I think the common name is red bistort.

 

[Sheal]

That does look a closer match to the plant you have. Below is a link for the RHS and it suggests the plant may be an irritant, so it's wise to handle it with care.

Persicaria amplexicaulis | red bistort Bogs/RHS

Find help & information on Persicaria amplexicaulis red bistort Bogs from the RHS

www.rhs.org.uk

 

[Kariha]

Yes I read the article on the RHS website, so I will be careful when handling the plant. A friend has also had a look and they said it's definitely not Japanese knotweed. Thank goodness. I was worried because the leaves were very similar and the stems have a slight zig zag. I think from the article I read, that's why it's often confused with knotweed.
Thanks for your replies.