No wy of knowing unless you add a photo to your question.

As Moon_Grower says impossible to tell without a photo, i've only seen blue flowering ones but that doesn't mean there isn't one, However it is grown for foliage and scent when crushed, so give a leaf the crush test and see how pungent it is...

As suggested, I've now managed to take and add a couple of pictures. I've also found one of the illustrated plant markers that came with the plants. This describes the plant as "coleus canina (green)".

I've since bought other coleus plants and they seem to bear little or no resemblance.

By the way, in reference to Surreylad, I've seen a comment "somewhere" that describes the scent as being like the smell of a mangy dog. Neither my gardener nor I can smell anything like that. But I'm no expert on mangy dogs!

Leaves don't look right for Coleus canina (now renames Plectranthus ornatus by the RHS), I know I should know this plant but having a senior moment.

thanks for the photo's, lol the smell is like wet dog smell not to pleasant, it's not coleus canina, it looks more like Sedum spurium 'Green Mantle' or something similar....

I think you may have got it Surreylad! I knew it was a Sedum couldn't remember which one - DHO!

Lol Moon_grower i get moments like that too... :-))

Moon_grower, Surreylad,
Thank you both for your attempts to identify these plants. I'm quite happy to accept that it is a Sedum. What would I know? Looking through the pictures available on here, I am inclined toward the picture posted by Nancym on 20 July, 2008. But I have found a picture on Google where I can compare the leaf shape.
http://www.wildchicken.com/nature/garden/nature_200_154.htm

What do you know? Sedum spurium 'Green Mantle'!

So, again, thank you very much.

your very welcome :-))

Enjoy!