Plant ID please

This arrived at the front of my border this summer; is it a weed? Or it might have come from the remains of a 'wildflower seed mix' I was given earlier this year - that certainly contained some non-native, non-wild flowers such as cosmos and iberis.



Here's a close up of the inconspicuous flowers, purple fading to white. (Ignore the dead leaves to the right - remains of a verbena bonariensis.) All ID help gratefully received! It looks as if it could form quite an attractive little mat, given the chance - and provided it's not going to try and take over.

 

It looks as if it has square stems @Clare G so it could be a sage, salvia or mint. I don't recognise the flower but the leaves do look sage-like. Do the leaves have a scent when you crush them?

 

The leaves look very salvia like to me.

 

Looks like a sage (salvia)

 

Thanks everybody; yes the stems are square. No scent worth speaking of, even if I crush a leaf or a flower. If it is a salvia that is good news, as I love salvias . I will leave it be and hope it makes it through the winter to flourish next year .

 

That's funny, salvias and sages have very scented leaves.

 

It's definitely not a weed, but looks like a short-living Salvia to me. Let's hope it survives winter.
Leave it as it is and hopefully, it gets new grow in Spring time, and then you can cut it down.

 

I have that in the garden, and it definitely isn't a salvia, but I can't remember what it is. Leaves are slightly fuzzy rather than really sharp. I collected seed from a plant up near the farm a few years ago. I thought it was a dead nettle of some kind, but it doesn't have the serrated edges or the broader foliage they have. Sorry - don't have any photos.
The pollinators like it, but - it spreads like mad though, so watch out for runners popping up nearby if you keep it.

 

A lot do and can be identified by smell, however some have little or no scent. Also in cold weather any scent is less noticeable.