84 ILLINOIS STATE ACADEMY OF SCIENCE 



A NEW MUSHROOM 

 W. B. McDougall, University of Illinois 



During the past few years I have been collecting in the 

 University Woods near Urbana, Illinois, and occasion- 

 ally at other places, a pretty little mushroom which very 

 evidently belongs to the genus Marasmius but which so 

 far as I have been able to learn is undescribed. (Fig. 1.) 

 The plant is especially interesting because it always is 

 attached to buried nuts. It is usually attached to walnuts 

 or butternuts of the preceding year but occasionally it 

 has been found attached to hickory nuts. 



The substratum that the mushroom makes use of seems 

 to be the nut shell rather than the meat. The meat of 

 the nuts to which the mushrooms are attached looks 

 normal and tastes normal. Sections of the meat washed 

 in alcohol show under the microscope normal parenchyma 

 cells full of crystaloid and globoid protein grains but 

 with no sign of mycelium. On the other hand sections 

 of a partly decayed half shell of a butternut to which a 

 mushroom was attached showed mycelium present in the 

 shell. 



Because of the substratum on which 'this mushroom 

 grows I am calling it Marasmius nucicola. A description 

 follows : — 



Marasmius nucicola n. sp. — Pileus 5-15 mm. broad, at 

 first campanulate, becoming nearly plane or umbonate. 

 Striate half way to the center, glabrous, reddish yellow to 

 lemon yellow, fading to nearly white. Flesh thin, mem- 

 branous. Gills adnate, moderately broad, not crowded, 

 white or pale yellowish. Stem 3-4 cm. long, slender, 

 smooth, reddish yellow to pale lemon yellowish, often 

 darker above. Long, hairy, rooting base often 5-7 cm. 

 long, extending and attached to a buried nut. Spores 

 oval with a very short apiculus, 4-5 mu. x 8-9 mu., smooth, 

 white. Odor none. Taste not pronounced. Edibility not 

 tested. Cystidia numerous on edge of gills. 



Under walnut and butternut trees in woods. Always 

 attached to buried nuts of Juglans or occasionally of 

 Carya. Often 3 or 4 sporophores are attached to the 

 same nut. August to October. 



