Sorry no name, I am sure it is a weed, it grows in my lawn given the chance.

Bugle, ajuga vulgaris.

It's ajuga.

There are dozens of cultivated varieties sold as rockery plants. the leaves can vary from dark brown to purple and there are several variegated forms .

It self seeds easily and if planted close to a lawn will often grow there quite happily even if mowed weekly.

If you google images "ajuga" you'll see lots of good photos

I've a grass area politely referred to by my friends as a "meadow lawn" (!) (mown at need in the Spring & Summer, but not de-weeded, it's in the midst of hilly countryside, so, surely little point to?) and in it, the recent flowering early in the season, of seedlings of ajuga like this (v. intense blue flower on my version of it), combined with cheeky dandelions and daisies, cheered my heart, and the bees', both!

'Weed' it surely may be - but: Food for their "hungry gap", and cure for any S.A.D. ...

Add wild violets both white and blue, and the odd cheeky primrose (all of which flourish further down the plot under a massive pine-tree), and sometimes I know why nature so quickly makes us forget Winter!