446 



The Suchti^y Ii^l-sm eliding Russula (Not Edibi^e;) 

 Ritssida foctcntula Peck 



This mushroom usually occurs in the woods, often among fallen 

 leaves, though I have found occasional specimens under trees on lawns. 

 The specimens from which the accompanying photograph was made 

 were collected among white oak trees in the "forestry", an artificial 

 wood-lot on the campus of the University of Illinois. 



This species is very easily recognized. The cap is nearly spherical 

 at first, but when fully expanded is fiat or somewhat depressed in the 

 middle. It is rather thin, smooth but cjuite viscid, and conspicuously 

 striate on the margin. The color is reddish yellow\ The odor is like 

 that of bitter almonds, and the taste is slightly bitter. The cap is 

 4 to 8 cm. (1.5 to 3 inches) broad. 



The gills are thin and narrow and quite close together. They are 

 attached to the stem but sometimes are very nearly free from it, and 

 are whitish in color but not pure white. The spores are very pale 

 yellow when collected in mass. 



The stem is firm and smooth and often hollow. It is white or 

 yellowish white in color but is usually stained with reddish brown 

 spots at the base. The stem is usually from 2.5 to 5 cm. ( i to 2 

 inches) long. There is no ring and no volva. 



R. foctcntula was described by Dr. Peck in 19,06 from specimens 

 collected in New York. It seems not to have been found commonly 

 elsewhere but it is common at Urbana and undoubtedly it occurs in 

 other parts of the state as well. It may be looked for from the middle 

 of June until late in August. It usually occurs singly, that is, not in 

 dense clusters, although a considerable number of specimens may be 

 found on a very small area. 



An interesting thing about this mushroom is that it forms ecto- 

 trophic mycorrhizas (see page 424) on the roots of the white oak 

 {Oucrciis alba). The genus Russula contains a large number of 

 species all of which produce their fruit bodies during the summer, and 

 it is probable that a number of them are capable of producing my- 

 corrhizas. R. foctcntula, however, is only the second one of the genus 

 to be definitely reported as a mycorrhiza-former. 



This species is not poisonous but it is not classed as edible because 

 it has not only a disagreeable odor but a disagreeable taste as well, 

 and would spoil the taste of any other mushrooms with which it might 

 be cooked. 



Collected in Champaign county. 



