THE FUNGI WHICH CAUSE PLANT DISEASE 445 



It parasitizes sugar cane, horse cliestnut, chestnut, mulberry" 

 and orange. 



Fig. 310. — S. alneum. After Clemtnts. 



Marasmieae (p. 443) 



Pileus tough, leathery, thin, membranous, or rarely somewhat 

 fleshj% reviving after dr>dng with the return of moisture. 

 About five hundred fifty species. 



Key to Gexeka of Marasmieae 



Gills leathery-horn}' ; spores black 1. Anthracophyllum. 



Gills leathery ; spores hyaline 

 Pileus not distinct from the stipe; sporo- 

 phore trumpet-shaped 



Gills forked, edge blunt 2. Xerotus. 



Gills wth a thin edge 



Gills toothed on the margin 3. Lentinus, p. 445. 



Gills with an even margin 4. Panus, p. 446. 



Pileus distinct from the stipe 

 Annulus wanting 



Pileus firm and dry 5. Marasmius, p. 446. 



Pileus somewhat gelatinous 6. Heliomyces. 



Annulus present 7. Merasmiopsis. 



Lentinus Fries 



Sporophore trumpet^shaped, pileus and stipe not distinct, 

 leathery, pileus central or lateral, gills toothed; spores white. 

 About three hundred forty species. 



