THE FUNGI WHICH CAUSE PLANT DISEASE 609 



Conidia not connected by isthmi 7. Septonema. 



Conidia connected by isthmi 8. Polydesmus. 



Fertile hyphsB distinctly different from 

 the conidia 

 Conidia solitary or nearly so, acrog- 

 enous for the most part 



Conidia muticate 9. Helminthospora. 



Conidia echinulate 10. Heterosporium, p. 610. 



Conidia smooth 



HyphiE creeping, radiate 11. Ophiotrichum. 



Hyphae short, ascending or 

 erect, conidia ovoid to 



oblong 12. Napicladiiun, p. 611. 



Hyphse longer, rigid; conidia 

 ovoid to elongate 



Conidia ovoid 13. Brachysporium. 



Conidia elongate 14. Helminthosporium, p. 611. 



HyphsB flexuous, pannose 15. Drepanospora. 



Conidia 1 to 3-ciliate at apex 16. Camposporium. 



Conidia verticillate or capitate 

 Hyphae dark 

 Conidia acrogenous, forming a 

 head 



Hyphae simple 17. AcTothecium. 



Hyphs branched at the apex. 18. Atractiiia. 

 Conidia pleurogenous, some- 

 what verticillate 

 Hyphae rostrate and naked at 



apex 19. Rhynchomyces. 



Hyphae not rostrate at apex. . 20. Spondylocladium, p. 614. 

 Hyphae hyaline or bright colored, 



apex denticulate 21. Neomichelia. 



Conidia catenulate as a rule 

 Conidia arising from the interior of 



the hyphae IV. Sporoschismes. 



Conidia arising from the apex, 



sometimes solitary V. Dendryphiese, p. 615. 



Clasterosporium Schweinitz (p. 608) 



Hyphse creeping, here and there swollen, erect, bearing 2 to 

 several-septate, solitary, apical conidia. 



