The dried fruit body of Fomes laricis (Jacq.) Murrill (Polyporus officinalis Fries), Polyporaceae, deprived of its outer rind. Habit. European and Asiatic Russia. Grows upon various species of Pinus, Larix, and Picea. Constit. 14-16% Agaricic acid; agaricoresin, agaricol, phytosterin, ricinoleic acid, cetyl alcohol, glucose, malic acid, carbohydrates. Isoln and separation of some constituents: Valentin, Knütter, Pharm. Zentralhalle 96, 478 (1957). Impregnated with potassium nitrate and dried, it constitutes punk or tinder.