At this moment the little Cutleaf Selfheal (Prunella laciniata) is in full bloom in limestone meadows. It loves the sun, so it is very happy those days!
It is a Lamiaceae, with a square stalk and opposite leaves, in fact the whole plant has something square and symmetric. There are other selfheals, but those mostly have blue flowers (like as an exemple 'Truncate Selfheal').
In the pictures it is surrounded by other flowers of this habitat. Above by Slender Bedstraw (Galium pumilum), and below by Horseshoe Clover (Hippocrepis comosa).