Field scabious (Knautia arvensis) 

 

Collins, 236; Readers Digest,

This is a very welcome and attractive tall hairy perennial.  It flowers from June to October and the flowers are bluish through to lilac with flat flower heads comprising as many as 50 individual flowers.  It has been used for treatments of skin diseases and has been drunk as an infusion and applied externally as an ointment. 

It is the diet of the caterpillars of several butterflies and moths.  Strangely sheep and goats will eat the plant but cattle dislike it.