CLASSIFICATION OF AGARICS 233 



plish-brown lines appear and when old, most gills :i j»i »«*ii i- blackish- 

 brown because of the dense layer of spores. The STEM is either 



almost iiiiilill'eieii! iated within and is then solid, or has a distinct 



pith which soon disappears and Leaves it hollow, often in the form 

 of a narrow tubule. 1 1 is fleshy and when fresh has no cartilaginous 

 cortex; it is, however, of different texture from thai of the pileus 

 and easily separates from it. 



The VEIL is single or double. When double the substance 

 of the under layer is similar to that of the pileus and the base of 

 the stem and is probably a part of a universal cuticle. Sometimes 

 it is very voluminous and forms a large pendulous annulus, as in 

 P. placomyces and P. subrufescens. Usually it is quite thick and 

 persistent. The lower layer breaks off soonest, ceases expansion 

 and cracks into radial patches which remain on the under Bide of 

 the annulus; sometimes, as in /'. abruptibulbd) it is very evane- 

 scent. 



The genus may be divided into two sections based on the structure 

 Of the veil. The Friesian grouping is entirely artificial, and the 

 difference in the color of the young gills, used by some as a basis for 

 grouping, seems too variable a criterion for the purpose. 



K( .// to the Species 



(A) Plants large; pileus normally much more than 4 cm. broad. (See 

 P. campestris. » 

 (a) Growing in forests, thickets, groves, etc. 

 (b) Pileus white, not fibrillose-scaly, usually glabrous. 



(c) Pileus turning yellowish on disk when nibbed; stem with 



small, abrupt bulb. 22»1. P. nhru ptibulbd Pk. 

 (cc) Pileus firm. Chalky-white, not stained yellow; without abrupt 

 bulb. 223. /'. cretacella Atk. 

 (bbi Pileus with fibrils or flbrillose scales <>n the Burface. 



(c) Flesh turning pink to blood-red where broken; fibrils brown- 



ish-gray. 231. P. haemorrhodaria Fr. 

 (cc) Flesh not or scarcely changing color. 

 (i!i Annulus single,, not covered on under side with floccose 



patches; fibrils brown. 230. /'. silvatiCQ Fr. 

 (dd) Annulus double, as shown by the patches on under surface. 

 (e) Disk of pileus blackish, fibrils brown; odor not marked. 



227. P. placomyces Pk. 



(ee) Disk reddish-brown, fibrils tawny; odor of almonds; la: 



228. P. subrufescens Pk. 



(aa) Growing in fields, open places, cultivated grounds or lawns, not 

 scaly, 

 (b) Annulus as a broad band with spreadin : gills very nar- 



row as compared to the thick flesh; in cities. 22 t. P. rodmotli 

 Pk. 

 (hb) Annulus different. 



(c) I 'ileus large, surface stained yellowish on disk" when brui 



annulus double. 225. P. arvensis Fr. 

 (cc) Pileus medium, surface unchanged; annulus lacerated, sin:; 

 gills bright pink. 229. P. vu pi ttris Fr. 



