152 THE AGARICACEAE OP MICHIGAN 



Bresadola, Fungii. maiig. e. vel., PI. 68. 



Marshall, Mushroom Book, PI. 17, p. 68, 1905 (reduced). 



Gibson, Edible Toadstools and Mushrooms, PL 13, p. 139, 



1903 (reduced). 

 Atkinson, Mushrooms, PI. 36, Fig. 4, 1900 (reduced). 

 Mcllvaine, American Fungi, PL 41, Fig. 2, 1900. 



PILEUS 5-10 cm. broad, fleshy, soon fragile, convex to piano-de- 

 pressed, rosy to Mood-red, sometimes faded to white, pellicle 

 separable, margin strongly tuhercular-striate or even sulcate, viscid 

 and shining. FLEBH white, red under the cuticle. GILLS pure 

 ivhite, subdistant or close, distinct, rather broad, equal, broadest 

 toward front, narrowly adnexed or free, interspaces venose. STEM 

 4-7 cm. long, 1-2 cm. thick, white or tinged red, subequal, spongy- 

 stuffed, even. SPORES white in mass, globose, echinulate, 7.5-10 

 micr. TASTE very acrid. ODOR none. 



Scattered or gregarious. On the ground or on debris of very- 

 rotten logs in woods. Throughout the state. July to October. 

 Common. 



The mycelium has been found to be attached to oak tree roots 

 where it forms mycorrhiza. The very acrid taste gives it a bad 

 reputation and it is avoided by mushroom-eaters. Some think it 

 is harmless when thoroughly cooked. There are variations of hab- 

 itat. It grows quite constantly on the crumbling remains of wood 

 or logs, where its white strings of mycelium are easily seen; here 

 the gills are close. One form has been found growing in troops; 

 such were found in a tamarack swamp in late October, growing on 

 thick beds of sphagnum. They had developed somewhat differently 

 in this habitat as was to be expected. The stems were white, long 

 and stout, narrower above and obsoletely wrinkled. The gills were 

 subdistant. The taste was sharp but not as excruciating as that of 

 the type. The disk of the pileus was glabrous and very viscid. It 

 was a beautiful plant, apparently appearing late; it might be re- 

 ferred to as var. gregaria. 



130. Russula rugulosa Pk. 



N. Y. State Mus. Rep. 54, 1901. 

 Illustration : Ibid, PL 72, Fig. 12-18. 



PILEUS 5-10 cm. or more broad, thin, fragile, convex then piano- 

 depressed, dark rose-red, color sometimes thin, surface almost en- 

 tirely rugulose, the rugae radiating somewhat, rather viscid, pellicle 



