This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
This local elusive species is found south of Holland, and in N. Africa in the North Temperate Zone. In Great Britain it is found in the Peninsula province, except in N. Devon, and in the Channel province; in the Thames, Anglia, and Severn provinces, except in Monmouth; in the Trent province, except in N. Lines and Notts; and in the Humber province, in Durham, and Haddington. Watson regards it as scarcely a true colonist. It occurs in the north from Durham to Cornwall and Kent, chiefly in the eastern counties. It is an introduction in Scotland.