S4 STUDIES OF AMERICAN FUNGI. 



decurrent (extend downward on the stem), are white, or whitish, 

 becoming in age more or less dingy or stained. The spores are 

 rounded or elliptical, 6-9 yw. The stem is elastic, spongy within and 

 sometimes hollow. It is smooth or often rloccose scaly below the 

 ring, sometimes with prominent transverse bands of a hairy sub- 

 stance. It is usually whitish near the upper end, but dull brown or 

 reddish brown below the annulus, sometimes distinctly yellowish. 

 The veil varies greatly also. It may be membranaceous and thin, or 

 quite thick, or in other cases may be absent entirely. The ring of 

 course varies in a corresponding manner. As shown in Fig. 85 it is 

 quite thick, so that it appears double on the edge, where it broke 

 away from the inner and outer surfaces of the margin of the cap. It 

 is frequently fixed to the stem, that is, not movable, but when very 

 thin and frail it often disappears. 



The honey colored agaric is said by nearly all writers to be edible, 

 though some condemn it. It is not one of the best since it is of rather 

 tough consistency. It is a species of considerable economic import- 

 ance and interest, since it is a parasite on certain coniferous trees, 

 and perhaps also on certain of the broad-leaved trees. It attacks the 

 roots of these trees, the mycelium making its way through the outer 

 layer, and then it grows beneath the bark. Here it forms fan-like 

 sheets of mycelium which advance along both away from the tree 

 and towards the trunk. It disorganizes and breaks down the tissues 

 of the root here, providing a space for a thicker growth of the mycel- 

 ium as it becomes older. In places the mycelium forms rope-like 

 strands, at first white in color, but later becoming dark brown and 

 shining. These cords or strands, known as rhi^omorphs, extend for 

 long distances underneath the bark of the root. They are also found 

 growing in the hollow trunks of trees sometimes. In time enough 

 of the roots are injured to kill the tree, or the roots are so weakened 

 that heavy winds will blow the trees over. 



The fruiting plants always arise from these rhizomorphs, and by 

 digging carefully around the bases of the stems one can find these 

 cords with the stems attached, though the attachment is frail and 

 the stems are easily separated from the cords. Often these cords 

 grow for years without forming any fruit bodies. In this condition 

 they are often found by stripping off the bark from dead and rotting 

 logs in the woods. These cords were once supposed to be separate 

 fungi, and they were known under the name Rhi%pmorptia subcor- 

 ticalis. 



Armillaria aurantia Schaeff. (Tricholoma peckii Howe) Suspected. 

 This is a very pretty species and rare in the United States. The 



