THE FUNGI WHICH CAUSE PLANT DISEASE 506 



C. wemsdorffise Kock occurs on roses. 

 C. hellebori C. & M. is found on hellebore. 



Sphserioidaceae — Hyalodidymse (p. 480) 

 Conidia hyaline, 1-septate, ovoid, ellipsoid or oblong. 



Key to Genera of Sphsrioidacese — ^Hyalodidyma 



Pycnidia separate 

 Pycnidia not beaked 

 Pycnidia in discolored areas, maculicole 

 Pycnidia immersed, then erumpent, 

 perforate 



Conidia muticate 1. Ascochyta, p. 506. 



Conidia with setse at the apex. ... 2. Robillarda. 



Pycnidia superficial, astomous 3. Pucciniospora. 



Pycnidia not macuhcole 



Pycnidia hairy 4. Didymochata. 



Pycnidia smooth 

 Conidia with an appendage at each 

 end 

 Conidia with 1 or more bristles . 5. Darluca. 

 Conidia with cap-like append- 

 ages 6. Tiarospora. 



Conidia muticate 

 Conidiophores 1-spored 



Pycnidia without subicle 7. Diplodina, p. 509. 



Pycnidia on a cobwebby subi- 

 cle, phyllogenous S. Actinonema, p. 508 



Conidiophores several to many- 



spored 9. Cystotricha. 



Pycnidia beaked 10. Rhynchophoma. 



Pycnidia in a stroma 

 Stroma effuse 

 Stroma consisting of two distinct 



layers H- Thoracella. 



Stroma of a smgle layer 12. Placosphserella. 



Stroma verruciform 



Stroma superficial 13. Patzschkeella. 



Stroma erumpent 14. Cytodiplospora. 



