Wilkinson grafted cuttings from a figured walnut tree and saw evidence in the offspring 22 years later.

NPR: Excerpt: 'A Splintered History Of Wood'

Welsh Abergavenny for its recently Michelin-starred Walnut Tree and Black Mountains lamb, and Manchester-neighbour Ramsbottom for its wild garlic and South Indian cuisine.

BBC: Birmingham takes the culinary crown

They can occur on any tree, anywhere, but are commonly found on elm, walnut, cherry, redwood and (again) our old friend and free-spirited, maple.

NPR: Excerpt: 'A Splintered History Of Wood'