HYDNUM. 



433 



Hydnum Schiedermayeri Heufl. (U.S. America). Sporo- 

 phores tleshy, with a sulphur-yellow colour both outside and 

 inside, and with a smell of anise. They occur on living 

 apple-trees, less frequently on other species of Pi/ms. Accord- 

 ing to Schroeter, Thiimen, and 

 Ludwig, the mycelium spreads 

 through the stems and kills 

 the trees. 



Thiimen ^ thus describes the 

 diseased wood of the apple: "It 

 has a greenish-yellow colour, 

 which passes over gradually 

 to the normal colour of the 

 wood : it becomes soft and 

 friable, smelling, like the 

 sporophore, faintly of anise." 



Sistotrema fusco-violaceum 

 Schrad. (Britain.) This accord in- 

 to Skiljakow^ is parasitic on living- 

 pines, entering by wounds, ami 

 carrying destruction tluouglmut 

 the wood. 



POLYPOREAE. 



Polyporus. 



Sporophores large and 

 usually shaped more or less 

 like a hoof or small bracket. 

 The sporogenous layer is com- 

 posed of cylindrical tubes, 

 which generally occupy the 

 lower surface of the sporophore. 



Fig. ■liiS.—Polyiwrus igyiiarius ou Oak. At 

 the upper end a wood-pecker's uest-holc. (v. 

 Tubeuf phot.) 



The substance between the tubes is different from that of the 

 rest of the sporophore. 



Polyporus (Fomes) igniarius (L.).=^ (Britain and U.S. America). 

 Sporophores on living stems of oak, alder, apple, willow, and other 



'Thnmen, " Ein Apfelbaum-Schadling."' Zeitsch. /. Pflanzmkrankhbite.i}, 1891. 

 -' Skiljakow, Scripla botan. horli universitatis Pitro/ioll/anae, 1890. 

 ^R. Hartig, Zervetzungstrscheinunrjtn, PI. XV. and XV'I. 

 2e 



