M BSi CT/OA HYGROCYBJ !fl5 



85 



Hygrophoms olivascens Sm. c\ Hes. 



Sydowia 8: 328. l c ni 



Pileus LO-25 mm broad, obtuse with an incurved margin, expand- 

 ing to piano or with a low flattened umbo, w hen young "chamois" \\ itb 

 a smoky brown cast, becoming a clearly chamois color at maturit) and 



then somewhat translucent, when faded opaque and pale bull, moist. 



hygrophanous, surface glabrous, becoming fibrillose squamulose as in 

 //. miniatus. Context very waxy and brittle, pale water) yellow I paler 



than pileus) or concolorous with pileus surface, when broken staining 

 brownish; odor sharp and Fragrant, taste slightly acidulous. 



Lamellae depressed-adnate. concolorous with t'd^<> ot pileus. 

 whitish in age. distant to subdistant, broad, edges with a tendency to 

 stain olivaceous where bruised. 



Stipe 4-6 mm long, .5-8 mm thick, concolorous with pileus or 

 brownish spotted from handling, equal or narrowed below, glabrous 

 and naked. 



Spores 7-8.5 x 4.5-5.5 /*, ellipsoid, hyaline to pale yellowish in Mel- 

 zer's reagent, smooth but as revived in KOI I often appearing granulose 

 but under oil immersion the granules or droplets are found to be just 

 inside the wall. Basidia 30-48 X 7-9 /x, clavate, the lower half often 

 flexuous, 4-spored. Pleurocystidia and cheiloc) stidia none. Gill trama 

 parallel or nearly so, hyaline in KOH, hyphae 4-7 p broad. Pileus trama 

 hyaline and interwoven, with fascicles of hyphal end-cells projecting 

 as the squamules. Clamp connections present in the cuticular hyphae. 



Habit, Habitat, and Distribution — Gregarious on humus, in 

 climax beech-maple forest, Michigan, July. 



Material Studied — Michigan: Smith 39276 (type, from Tahqua- 

 menon Falls State Park, July 24, 1952). 



Observations — The smoky brown color of young caps, the sharp 

 fragrant odor, and tendency of the gill edges to stain olivaceous are dis- 

 tinctive field characters. The species appears to be most closely related 

 to H. caespitosus Murr. but differs in the olive-staining gills and tend- 

 ency of the stipe to stain brownish where handled. 



Hygrophorus caespitosus (Murr.) Murr. 

 Mycologia 6: 2. 1914 



Hydrocybe caespitosa Mun.. Mycologia 6: 2. 1914. 



Camarophylhts caespitosus Murr.. North Amer. Flora 9: 387. 1916. 



