362 DISEASES OF CULTIVATED PLANTS 



these under certain conditions may become true parasites. 

 It is considered that the mycelium of many species may be 

 parasitic in the living tree, but that, as a rule, sporophores 

 are only produced after the tree is dead. The following are 

 included by him in this category. 



Lenzites sepiaria (Fr.). Occurs very frequently on old 

 stumps of Scots fir, less frequently on living trunks of the 

 same tree, and abundantly on the worked wood. 



Lenzites abietina (Bull.) occurs abundantly on stumps of 

 pines and silver fir. 



Lenzites betulina (Fr.) is common on stumps of birch, 

 oak, and beech ; less frequently on living trunks. 



Lenzites variegata (Fr.). On stumps of birch and oak, and 

 on living trunks of beech, poplar, and Prunus avium. 



Lentinus squamosus, Fr. ( = L. lepideus, Fr.), especially on 

 stumps of Scots fir. 



Lentinus conchatus (Fr.). On trunks of poplar and silver 

 birch. 



Panus stypticus (Fr.). Abundantly on stumps ; also on living 

 trunks of alder, hazel, birch, and beech. 



Paxillus panuoides (Fr.). On stumps of Scots fir. 



Psathyrella disseminata (Fr.). On stumps of many broad- 

 leaved trees, especially birch. 



Psilocybe spadicea (Schaeff.). Very abundant in dense tufts 

 on stumps and roots of various broad-leaved trees. Less 

 frequently on living trunks of lime, elm, willow, maple, and 

 beech. 



Hypholoma appcndiculatum (Bull.). Everywhere on stumps, 

 and on roots of living trees ; especially willows, poplars, beech, 

 and lime. Probably parasitic on roots. 



Hypholoma fas ciculare (Huds.). Abundantly on stumps of 

 both conifers and broad-leaved trees ; also on living trunks 

 of oak, poplar, elm, and Scots fir. Probably a true parasite 

 at times. 



Hypholoma lateritium (Schaeff.). Abundant in clusters on 

 stumps of beech, birch, maple, horse-chestnut ; also on living 

 beech trunks. 



Flammula alnicola (Fr.). On stumps ; less frequently on 

 living trunks of alder. According to Schroter it occurs on 

 trunks of lime, elm, and willow, and is a root parasite. 



Pholiota squarrosa (Mull.). Very frequently on trunks of 

 various kinds of broad-leaved trees. 



Pholiota aurivella (Batsch.). Less frequently than the 



