On my whishlist : Vegetables by Roger Phillips and Martyn Rix.
Amazon: "The only single-volume guide to vegetables any gardener could need. Illustrated throughout with color photographs that show the different kinds of each vegetable and how they look in situ, the book documents more than 650 types of vegetable, mainly those that can be grown in North America and northern Europe, but includes popular Asian specialties. Each is accompanied by descriptions of the vegatble's history and its cultivational needs.
Though not mainly a source of gardener's tips, the book offers simple instructions to the grower, as well as fodder for anyone curious to know more about the first European sighting of potatoes (1537) or the multitudes of possible potatoes ("Duke of York"; "Epicure"; "Mona Lisa")." Oct 2007 edition For sale at Amazon.co.uk