636 THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Genera of PhseostUbese-Amerosporie 



Conidia not in chains 



Synnema setose I. Saccardsa. 



Synnema naked 

 Conidia asperate, on minute basidia. . . 2. Basidiella. 

 Conidia smooth 

 Synnema camose, racemose-branched 3. Stjlbothamnium. 

 Synnema fibrous or corneous, not 

 racemose 



Conidiophore lageniform 4. Ceratocladium. 



Conidiophore lacking, at least not 

 lageniform 

 Synnema stalked, fibrous 

 Conidia dark, globose to ellip- 

 tic 5. Sporocybe. 



Conidia hyaline 

 Conidia ovoid to oblong. . . 6. Graphium. 

 Conidia elongate or falcate. 7. Harpographium. 



Synnema sessile, corneous 8. Glutinium. 



Conidia in chains 



Syimema setose 9. Trichurus. 



Sjmnema not setose 



Stalk branched above 10. Stemmaria. 



Stalk simple or nearly so 

 Capitule loose 

 Base of synnema subequal; usually 



on stems 11. Stysanus, p. 636. 



Base of synnema perithecioid; 



usually on leaves 12. Graphiothecium. 



Capitule compact 

 Conidia globose 



Conidia echinulate 13. Harpocephalum. 



Conidia smooth 



Conidia pleurogenous 14. Heydenia. 



Conidia acrogenous 15. Briosia. 



Conidia ovoid to oblong 16. Antromycopsis. 



Stysanus Corda 

 Stromata erect, cylindro-clavate, dark, rigid; conidia in an oblong 



