ROSY-SPORED AGARICS. 



139 



varies considerably in size and appearance. It is 7-15 cm. high, the 

 cap 5-10 cm. broad, and the stem 6-12 mm. in thickness. It occurs 

 on the ground from underground roots or rotten wood, or grows on 

 decaying stumps, logs, etc., from spring until late autumn. Some- 

 times it is found growing in sawdust. 



The pileus is fleshy, bell-shaped, then convex, and becoming 

 expanded, the surface usually smooth, but showing radiating fibrils, 

 grayish brown, or sometimes sooty, sometimes more or less scaly. 

 The gills are not crowded, broad, free from the stem, white, then 



Figure 136. Pluteus tomentosulus. Cap and stem entirely white, gills flesh 

 color, stem furrowed and tomentose (natural size). Copyright. 



becoming flesh color with the maturity of the spores. One very 

 characteristic feature of the plant is the presence of cystidia in the 

 hymenium on the gills. These are stout, colorless, elliptical, thick- 

 walled, and terminate in two or three blunt, short prongs. 



The stem is nearly equal, solid, the color much the same as that 

 of the pileus, but often paler above, smooth or sometimes scaly. 



In some forms the plant is entirely white, except the gills. In 

 addition to the white forms occurring in the woods, I have found them 

 in an old abandoned cement mine growing on wood props. 



