THE AGARICACEAE OF MICHIGAN 



(ff) Stem white, rarely tinged yellow; pruinose-scaly at 

 apex; pileus sulcate-plicate. (See 534. BolMtius 

 vitellinus Fr.) 

 (ee) Pileus sulcate-plicate, not umbonate; stem citron-yellow. 

 537. P. expansus Pk. 



535. Pluteolus coprophilus Pk. 



N. Y. Siatc Mus. Rep. 46, 1893. 



PILEUS 24 cm. broad, fragile, conical campanulate then ex- 

 I anded, depressed on disk, viscid when moist, striatulate on margin, 

 whitish at first, soon rosy-gray or pinkish-cinnamon. FLESH thin, 

 submembranaceous. . GILLS free, narrow, crowded or close, pale 

 rusty-cinnamon, dotted by the spores. STEM 0-11 cm. long, 24 mm. 

 thick, straight or flexuous, slender, hollow, pure white, rarely tinged 

 willi pink, glabrous or obscurely squamulose, equal or attenuated 

 at base. SPORES oval-elliptical, smooth, variable in size, 12-18 x 

 7-10 uiicr., bright-cinnamon in mass. 



Caespitose or gregarious. On decaying straw piles, on compost 

 heaps or on dung, especially on lawns, fields, around trees, etc., 

 where coarse manure was used. Ann Arbor. Probably throughout 

 the State. May-June. Infrequent. 



During continued wet and sultry weather it is often very abundant 

 on manure mixed with straw. In June of one year specimens ap- 

 peared around every tree on the campus of the University of Michi- 

 gan where such manure had been deposited. Some think BolMtius 

 null mis Morg. is identical with it. 



536. Pluteolus aleuriatus gracilis Pk. 



Syst. Myc, 1821 (as P. aleuriatus Fr.). 

 X. V. Slate Mus. Rep. 54, 1901. 



PILEUS 12 cm. broad, fragile, soon expanded-plane, viscid, 

 striate sulcate on margin, hygrophanous, drab color to grayish- 

 brown, paler on depressed disk, glabrous. FLESH thin. GILLS 

 free or nearly so, narrow, close, whitish at first then pale rusty-cin- 

 namon. STEM 2.5-8.5 cm. long, 1.5-3 mm. thick, equal or narrowed 

 upwards, glabrous or minutely pulverulent, hollow, white, or pallid. 

 SPORES elliptical, smooth, 942x4-6 micr., pale ferruginous. 



Ob the ground among decaying leaves in mixed woods. Hough- 

 ion. Bay View. July. Rare. 



