804 THE AGARICACEAE OF MICHIGAN 



tuse at ends, white. CYSTIDIA none or few, then sublaneeolate 

 to subfusiform, 45-65 mm. long. Sterile cells ventricose below r 

 obtuse cylindrical above, abundant, 35-42 micr. long. ODOR 

 strongly a it rents. 



Caespitose, gregarious or solitary, on decayed logs and debris of 

 tamarack, elm, etc. Ann Arbor, New Richmond. May- June and 

 September-November. Not very common. 



Characterized by the odor, by the few cystidia, and the slippery 

 pseudo-viscous stem. The surface of the cap is composed of large, 

 brown, erect, vesiculose cells. There is no separable pellicle, and 

 the stem is not truly viscid, but feels gelatinous when applied to the 

 lips. It differs from M. ammoniaca in its slippery stem, lack of a 

 decurrent tooth at the attachment of the gills, and in the differently 

 shaped spores. In M. alcalina the spores are symmetrically ellip- 

 tical, in M. ammoniaca they are pip-shaped, i. e., narrowed and 

 pointed toward one end. Roth may he found on the decayed debris 

 of leaves and. wood on the ground and botli may occur solitary or 

 gregarious, although M. ammoniaca is rarely, if ever, caespitose. 

 Roth differ from M. metata, M. leptocephala and M. constans in the 

 marked excess of brown shades instead of gray. 



857. Mycena ammoniaca Fr. 



Epicrisis, 1836. 



Illustration: Cooke, 111., PI. 238. 



PILEUS 5-15 mm. broad, conic-campanulate, but obtuse (at first 

 elliptic-ovate i, nmbonate. hygrophanous, striatulate on margin, 

 glabrous, fuscous-blackish to grayish-brown (moist), grayish buff 

 or paler (dry). FLESH membranaceous, concolor. GILLS adnate, 

 uncinate, close to subdistant, narrow and linear, interspaces venose 

 at times, whitish then pale cinereous, often dark cinereous at the 

 very first. STEM 3-5 cm. long. 1-1.5 mm. thick, toughish, equal, 

 straight, hollow, even, not slippery, whitish to pale brownish-ashy, 

 white mycelioid at base, scarcely rooting. SPORES 8-10 x 6-7 micr., 

 pip shaped, or elliptical-ovate, pointed at one end, smooth, white. 

 CYSTIDIA none or few, short, stout, ventricose and obtuse, 36-40 x 

 15 micr. RASIDIA about 30x6 micr., slender. ODOR strongly 

 nitrous. 



Gregarious or scattered among leaves, remnants of decayed wood, 

 etc. Ann Arbor, New Richmond. May-June and September-Octo- 

 ber. Infrequent. 



