This might possibly be Echinops exaltatus which is an introduction from Europe which has very occasionally escaped from nearby gardens and naturalised itself successfully on roadside verges. The Echinops genus is a tricky one to characterise so this is only a tentative identification. It has been suggested by better botanists than myself that particular specimen is nearer to Echinops bannaticus than Echinops exaltatus so I'll leave it as Echinops sp.

Roadside verge near St Helens, Lancs, 23rd July 2005

Added on October 24th 2005, updated 16th December 2008, updated 29th March 2010, updated 30th December 2018