PLEUROTUS. 371 



A very variable spacies ; according to Kalchbronner, the 

 spores have a faint tinge of lilac, and the pileus is white, 

 tawny, brownish, or umber on the same trunk, The white 

 form only has been met with in this country. 



Pleurotus mutilus. Fr. 



Pileus up to 1 in. across, flesh rather thick, soft, irregu- 

 larly circular iu outline and slightly depressed, but very 

 variable in form, glabrous, silky when dry, white; gills de- 

 current, somewhat crowded, narrow, rather thick, simple ; 

 stem about -\ in. long, slender, expanding upwards into the 

 flesh of the pileus, excentric or almost lateral, glabrous, base 

 downy, white. 



Agaricus (Plcnrotus) mutilus, Fries, Syst. Myc., i. p. 191 ; 

 Cke., Hdbk., p. 104; Cke., Illustr., pi. 275B. 



On the ground among grass. Cooke says, also on dead 

 wood. 



Very similar to Omplialia scyplioidcs, Fr. ; of which it may 

 possibly be a variety; but although the two have grown 

 mixed together, I have never observed a direct transition. 

 P. mutilus differs in being almost glabroiis, never regular in 

 form, and not iufundibnliform. (Fries.) 



**** Gills dccurrent ; stem lateral, sliorl or absent. 



Pleurotus ostreatus. Jacq. 



Pileus 3-6 in. across, fleshy, soft, at first convex and hori- 

 zontal, then expanded and ascending, glabrous, moist, even, 

 but the cuticle sometimes torn into squamules, dark and 

 almost blackish when young, then brownish-grey, clear 

 bluish-grey with violet tinge, or lavender colour, often 

 becoming yellowish when old; stem short or obliterated, 

 firm, obliquely ascending, incrassated upwards, white, base 

 downy or strigose; gills decurrent, anastomosing behind, 

 rather distant, broad, white, sometimes tinged yellow, never 

 pinkish; spores elliptical, white, 10-12 X 4-5 p. 



Agaricus ostreatus, Jacques., Austr., t. 268; Cke., Ildbk., 

 p. 105; Cke., Illustr., pi. 195 and 953. 



Pleurotus Columbians, Quelet, in Bresad., Fungi Trident., 

 p. 10, t. vi. 



On trunks. 



2 B 2 



