Touchwood, or Spunk, Boletus igniarius, L. a species of fungus, or sponge, which grows on the trunks, particularly those of cherry and plum-trees ; where it frequently extends to a size of from two to eight inches.

The substance of this vegetable is very hard and tough, of a tawny-brown colour, and is sometimes employed, both in England and in Germany, as a substitute for tinder : with this design, it is boiled in a strong ley, or urine, after which it is dried, and boiled a second time in a solution of saltpetre. It is also occasionally used as a Styptic; being collected in August and September; the hard external crust is separated, and the medullary part is beaten with a hammer, till it becomes soft.