236 THE FUNGI WHICH CAUSE PLANT DISEASE 



Perithecia without such a basal 

 growth 



Spores typically 1-celled 2. Massalongiella. 



Spores usually unequally 2-ceUed. 3. Guignardia, p. 237. 

 Spores 2-celled 

 Perithecia produced on living 



plants 4. Stigmatea, p. 243. 



Perithecia appearing after the death 



of the host 5. MycosphareUa, p.243. 



Spores dark-colored 



Spores 1-ceUed 6. MiiUerella. 



Spores 2-celled 



Lichen-inhabiting 7. Tichothecium. 



Not lichen-inhabiting 8. Phseosphsrella. 



Spores several-celled, hyaline 

 Spores elongate, with cross walls only 



Spores 2 to 4-celled; on Uchens 9. Pharddia, p. 250. 



Spores 4-celled; with a cottony subicu- 



liun 10. Sydowia. 



Spores many-celled H- Sphserulina, p. 250. 



Spores muiiform 12. Pleosplitenilma,p.250. 



Ascospora Fries (p. 235) 



Perithecia borne on a subiculum of thick, brown, much-branched 

 hyphse, globoid, black, carbonous; asci clavate, 

 clustered, 8-spored, small; spores 1-celled, hya- 

 line; paraphyses none. 

 About half a dozen species, one of which is 

 ^ ,„, . said by Vuillemin ^^ to be the ascigerous form 



Fig. 171. — ^Ascospora , _, "' , . , .. , 



himantia. Aaci. of Coryneum beyenncku, a wound parasite 

 After Winter. . . 



common on drupaceous trees causing gum- 

 mosis. Cultural evidence of this relationship is lacking, but his 

 hypothesis may be tentatively assumed. 



A. beyerinckii Vuil. Perithecia black, depressed-globose, apapil- 

 late; ostiole indistinct or absent, 100-130 ^ in diameter; spores 

 elliptic-fusoid, ends obtuse, continuous, hyahne, guttulate, 15 x 5- 



Conidia, 1. (=Phyllosticta beyerinckii) pycnidia globoid with 

 hyaline spores. 



