Can anyone tell me what this is I stumbled accross yesterday growing wild along a hedge?
Geranium molle aka dove's foot geranium - a European wildflower/weed.
Doesn't look like a geranium to me, more like a malva.
Yes, I was thinking malva (hollyhock) too.
That appears to be Malva sylvestris Mystic Merlin. Great plants for flower beds but does reseed itself. Not as bad at reseeding as the variety Zebrina though.
Malva sylvestris, Common Mallow. Flowers are variable from pale pink to purple. This is a particularly dark specimen but I think it unlikely to be a named cultivar, especially since it was growing wild along a hedge. A common wild flower in the British Isles.