AMADOU, a soft tough substance used as tinder, derived from Polyporus fomentarius, a fungus belonging to the group Basidiomycetes and somewhat resembling a mushroom in manner of growth.
Polyporus igniarius and other species are also used, but yield an inferior product.
In Germany a fungus (Polyporus Laricis) grows on the roots and stems of decaying larches, which was formerly in esteem as a drastic purgative.
Such aggregations of hyphae frequently become knotted up into dense masses of interwoven and closely packed hyphae, varying in size from that of a pin's head or a pea (Peziza, Coprinus) to that of a man's fist or head, and weighing io to 25 lb or more (Polyporus Mylittae, P. tumulosus, Lentinus Woermanni, P. Sapurema, &c.).
In many cases the swollen cell-walls serve as reserves, and sometimes the substance is so thickly deposited in strata as to obliterate the lumen, and the hyphae become nodular (Polyporus sacer, P. rhinoceros, Lentinus Woermanni).