Self-heal (Prunella vulgaris)

Collins 208; Readers Digest, 291

This is a low creeping perennial which is widely spread throughout our region.  It flowers from June to November with square purplish heads.  The stem and stalk are green.  The plant gets its name from the fact that the upper lip of its flower was believed to be in the shape of a hook and bill. Hooks and scythes were the main cause of wounds on farms in mediaeval times.  Therefore the shape of the flower led to the belief that this plant was a healer of wounds and it was also made into a syrup for internal injuries.  Very occasionally the flowers can be pink or white. 

See also: http://www.botanical.com/botanical/mgmh/s/selfhe40.html