NATURAL HISTORY SURVEY 49 



Pleurotus ostreatus Fr. 



Pileus fleshy, soft, convex or slightly depressed behind, sub- 

 dimidiate, often cespitosely imbricated, moist, glabrous, whitish, 

 cinereous or brownish; flesh white. 



Lamellae broad, decurrent, subdistant, anastomosing at the 

 whife or whitish. 



in when present, very short, firm, lateral, sometimes 

 strigose-hairy at the base. 



Pileus 5 to 10 cm. broad; spores oblong, white, 7.5 to 10 x 4 p.. 



Xot common, but found occasionally throughout our district, 

 chiefly after rains in autumn, on various deciduous trees. 

 'ff. A specimen found by Mr. Fred Wells, growing on Ulmus 

 americana, in his lawn, at Wheaton, consisted of a mass of imbri- 

 ' cat eel pilei extending down a diseased crevice in the tree-trunk 

 a m distance of 3 dm. The individual pilei were 7 to 12 cm. broad, 

 conchate, tapering to stem-like bases, smoky-white in color; 

 lamellae deeply and irregularly decurrent, the interspaces rugose- 

 reticulate toward the base. 



Pleurotus sapidus Kalch. 



Plant generally cespitose, pileus eccentric or lateral, rarely 

 e, irregular, convex or depressed on the disk, glabrous, 

 variable in color, whitish, yellowish, grayish-brown, lilac-brown 

 or smoky-brown; flesh white. 



Lamellae rather broad, subdistant, decurrent, distinct or 

 ornosmo- a t the base, whitish. 



111 firm, solid, straight or curved, white or whitish, often 

 united at the base. 



Spores oblong, pale lilac, 9 to 11 x 4 to 5 p. Pilaus 5 to 12.5 

 cm. broad; stern 2.5 to 6 cin. long, 6 to 16 mm. thick. 



i et, Wheaton, in sod where a street tree had been cut close 

 to the ground, the plants growing from the buried decaying stump 

 and roots. In dense, cespitose clusters, appearing for three 

 suc< -cr heavy rains, from August to October. 



Pleurotus mastrucatus Fr. 



Pileus mouse-gray, as if prickly with floccose, squarrose scales 

 of v the same color, fleshy, when full grown obovate or tongue- 

 shaped, soft, flaccid, margin involute but lobed when full grown 

 or luxuriant: stratum of flesh double, the upper gelatinous, pliant, 

 mouse-fuscous 1 mm. thick, the lower a little thicker, pallid. 

 -~ Lamellae at first connivent in an eccentric umbilicus, then 

 converging to the base of the pileus, broad, somewhat distant, 

 quaternate, whitish-gray. 



Big Woods, Evanston; September. Gammon. Jewell Grove, 

 Wheaton, November. 



i'ruf. Morgan notes of plants collected in Ohio, that the pileus 

 is "rough, with hairs and rigid points intermixed; somo of the 

 hairs or points blackish." The blackish points or scales are a 



