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.
Since about 1880 our knowledge of the species which can enter into such relationships has been materially extended, and the fungal constituents of the Lichens are known to include Basidiomycetes as well as Ascomycetes.
In the two genera of lichens - the Basidiolichens - i n which the fungus is a member of the Basidiomycetes, we have the fructification characteristic of that class of fungi: these are dealt with separately.
For some obscure reason the Basidiomycetes do not readily form lichens, so that only a few forms are known in which the fungal element is a member of this family.
In many Basidiomycetes minute branches arise below the septa; their tips curve over the outside of the latter, and fuse with the cell above just beyond it, forming a clamp-connexion.