FOMES APPLANATUS AND FOMES LEUCO- 

 PHAEUS. 



It is well known to those who are familiar with the subject that 

 the European species, Fomes applanatus, presents characters quite 

 different from those of its American analogue, Fomes leucophaeus. 

 The European species has a dark brown crust, rather soft; often you 

 can indent it with your thumb nail and easily cut it with a knife. 

 The American species has a hard, pale, horny crust, and if you want 

 to cut it you had better take an ax. Fomes applana'us is a European 

 plant, not (surely) known in America, though as has been pointed out 

 several times, our American species was for many years passed off as 

 being this plant of Europe. 



We have in America a very similar plant, Fomes reniformis, a good 

 species, I think, but a bad name. It has the same soft texture and soft, 

 brown crust as Fomes applanatus, but is an annual plant (hence, not 

 a true Fomes) while Fomes applanatus is a perennial plant. If Fomes 

 applanatus grew in the United States, it would be difficult to dis- 

 tinguish the first year's growth from Fomes reniformis, unless by the 

 spores. 



Fomes leucophaeus is the most common Fomes in the United 

 States. It occurs in Europe rarely, but when it does occur it is easily 

 distinguished from the common European species, and has been so 

 distinguished by all recent writers Bresadola, Patouillard, Rolland, 

 Boudier, etc. As to spores, Patouillard has published that leuco- 

 phaeus has smooth spores, and applanatus rough spores. That has 

 always been my understanding, though I have relied on Patouillard's 

 published statements. Atkinson has recently published that the 

 spores of F'omes leucophaeus and applanatus are both smooth, and 

 that they are the same species. I have examined a number of speci- 

 mens since and think he is right as to the spores, but it does not follow 

 that the plants are the same species", nor that the spores of all "Gano- 

 dermas" are smooth. I have observed our American species, reni- 

 formis, a number of times, and never questioned but that it has rough 

 spores, and am still of that opinion. Also lucidus, I believe, has 

 rough spores. Atkinson tells us that the spores are not rough, 

 that they only look rough under the microscope, and that this is 

 consequently an optical illusion. That may be true, but if it is an 

 "optical illusion" it is much more "illusive" in some cases than in 

 others. 



All three of these species are closely related, and many inter- 

 mediate, connecting forms occur, and all three can be held to be forms 

 of one species, as Atkinson alone holds, as to two ; or, they can be 

 considered as three different species, as everybody else now considers 

 them, including our own Mr. Murrill, at least in the last published 

 work I have seen from his pen. 



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