26 THE POLYPORACEAE OF WISCONSIN. 



§1. CoNiOPHORi. Hymenium powdered with the rust-brown spores. 



Merulius lacrymans (Wulf). 



Pileus widely effused, often .3 to .8 meters in extent, of membran- 

 aceous, or spongy-fleshy or leathery consistence, ochre-yellow or fer- 

 ruginous with white tomentose border. Pores large, unequal, gyrose 

 meshes; orange-yellow, becoming cinnamon-brown from the spores. 

 Spores egg shaped, one sided, intensely yellow-brown, 10 microns by 6 

 microns. 



On decaying wood, especially timbers in damp buildings and cel- 

 lars. 



Massee (17, p. 186) says that it grows "On trunks, worked wood, 

 carpets, etc., the patches varying from 2 to 3 inches to a foot and more 

 in diameter, l/^ inch or more, thick at times. Very variable, but dis- 

 tinguished by the slightly gelatinous substance, irregularly rugulose 

 hymenium, and bright rusty orange spores. Exuding drops of water 

 when growing." 



This is the so called "Dry rot" or "Hausschwamm" of Europe. 

 "Winter (28, p. 395) calls it the "foe of the homes, whose woodwork it 

 destroys". According to the same author the folds usually lengthen 

 in old age into teeth, giving rise to the following names: Boletus ob- 

 liquus Bolton; Sistotrema cellars, Persoon; and "Wallroth's Boletus 

 Jiydnoideus. 



Localities: Madison, Bangor. Some specimens were found in the 

 woods in the fall of 1903 growing on a charred stump, and some small 

 Bpecimens were found growing on the ground in a lumberyard, under 

 the lumber and on pieces of lumber lying on the ground. 



The specimens are all very irregular and thin and show well the 

 long strands or threads of white mycelium which run through the 

 wood. The margin is white, soft tomentose, not at all reflexed. The 

 hymenium begins about 4 mm. from the margin in very shallow pores 

 of a rusty yellow color. Toward the center the pores are much larger 

 and deeper, becoming almost brown. The folds are sometimes 

 toothed. 



Syn. : Xylomyzon destruens Pers. ; 23, vol. 2, p. 27. 



