102 SECTION HYGROTRAMA 



likely to be found here. The minute blackish punctae over the upper 

 part of the stipe should be a good field character. 



43 



Hygrophorus rugulosus Sm. & Hes. 



Sydowia 8: 330. 1954 



Pileus 8-12 mm broad, convex when young, broadly convex in age, 

 surface glabrous and rugulose, "buffy brown" to dark avellaneous in 

 buttons, becoming olive-buff and finally fading to whitish as if subhy- 

 grophanous. Context unchanging when bruised, firm but very brittle; 

 odor and taste none. 



Lamellae arcuate-decurrent, pinkish buff when young, becoming 

 avellaneous, concolorous with the pileus in age, thickish, subdistant, 

 medium broad, edges even. 



Stipe 1-2 cm long, 1.5-2 mm thick, equal or narrowed downward, 

 olive brown or grayer at apex, paler (pallid) below, in age more or 

 less concolorous with the gills (no yellow anywhere at any time), 

 naked, translucent. 



Spores 4—5 /x, globose or nearly so, smooth, hyaline, yellowish in 

 Melzer's reagent. Basidia 28-40 X 6-7 /x, 4-spored. Pleurocystidia and 

 cheilocystidia none. Gill trama somewhat interwoven, hyaline in KOH. 

 Cuticle a trichodermium but terminating in an hymeniform layer of 

 vesiculose to pedicellate-inflated cells (end cells of more or less up- 

 right hyphae), thin-walled and readily collapsing. No hypodermium 

 differentiated. Pileus trama radial, more or less parallel to interwoven. 

 Cell content of carpophore hyphae not distinctively colored in Melzer's 

 reagent. Clamp connections absent. 



Habit, Habitat, and Distribution — Gregarious on humus, Michi- 

 gan, August. 



Material Studied — Michigan: Smith 37565 (type, from Pellston, 

 Michigan, Aug. 10, 1951). 



Observations — The cuticle of the pileus does not become broken 

 into squamules as in H. cantharellus series, and the gill trama is more 

 interwoven than in the other species of that section. 



44 



Hygrophorus dennisianus ( Singer ) , comb. nov. 



Hygrotrama dennisianum Singer, Sydowia 12: 221. 1958. 



Pileus 4-4.4 mm broad, convex, thin with a convex to merely de- 

 clivous marginal portion and flattened to depressed disc, glabrous to 

 minutely pruinate, often rivulose-cracking, neither viscid nor hygroph- 



