MYCENA. 99 



On trunks and on the ground. 



Stem 1 in. and more long, l|-2 lines thick, base smooth; 

 gills almost 2 lines broad, shining, dark grey, margin 

 whitish ; pileus 1 in. broad, expanded, plano-convex, rather 

 wavy, grooves broad, distinct, opaque, substance very thin, 

 pellucid, appearing to be slightly downy, but really glabrous. 

 Taste unpleasant ; smell like sweet nitre. (Persoon.) 



M. alcalina differs in the sticky stem. In Cooke's figure 

 the gills are represented as slightly sinuate and with a 

 minute decurrent tooth. 



Agreeing with M. alcalina in the nitrous smell; differing 

 in not being caespitose, the slightly striate stem ; sulcate, 

 pruinose pileus, and emarginate gills. (Fries.) 



Mycena alcalina. Fr. 



Smell strong, nitrous. Pileus up to 1 in. across, flesh thin ; 

 campanulate, obtuse, margin at length spreading or some- 

 times upturned, deeply striate when moist, shining when 

 dry, colour various, pallid, or with a tinge of pale yellowish- 

 green, disc darker; gills adnate, narrowed behind, rather 

 distant, whitish then glaucous or greyish; stem 2-3 in. long, 

 1 line thick, equal, pale, sometimes yellow, shining, slightly 

 viscid, base downy, hollow ; spores 8 x 5 /x. 



Agaricus (Mycena) alcalinm, Fries, Syst. Myc., i. p. 142; 

 Cke., Hdbk., p. 83; Cke., Illustr., pi. 187B, 225. 



On trunks and stumps, among leaves, &c. 



On trunks (somewhat tufted), leaves, &c., not truly terres- 

 trial, as in M. ammoniaca. Smell strong, nitrous. Pileus 

 without a viscid, separable pellicle ; stem not truly viscid. 

 Very variable in size and colour. Stem yellow, grey, &c. ; 

 gills rather thick, slightly connected by veins, often dark 

 grey, edge paler, yellowish-glaucous, &c., rigid but fragile. 

 (Fries.) 



M. ammoniaca has the same smell as the present species, 

 but differs in growing on the ground; slightly striate, 

 umbonate pileus ; stem without a yellow tinge. 



Solitary or densely caespitose. Pileus |-2 in. broad, sub- 

 carnose, umbonate, subuni Donate or quite obtuse, even, with 

 or without imbedded fibrillae, at first conico-p;ipillate, rugose, 

 cinereous or tinged with olive, substriate, when old expanded 

 or depressed but little changed in colour, though occasionally 



H 2 



