THE FUNGI WHICH CAUSE PLANT DISEASE 191 



Dimerosporium Fuckel (p. 189) 



Perithecia depressed-globose, membrano-carbonous; asci clavate 

 to ovate, 8-spored; spores 2-celled, hyaline or brownish; mycelium 

 abundant, dark, forming a film and often bearing conidia on 

 conidiophores. 



D. mangiferum Sacc. does some harm to the mango. 



D. pulchrum, Sacc. grows upon the leaves of several woody 

 plants, such as privet, Lonicera, Carpinus and 

 Cornus. Conidia=Sarcinella heterospora. 



D. ct)llinsii (Schw.) Thiim., forms witches 

 brooms on the service berry. 



Lasiobotrys Kunze (p. 189) 



Fig. 138.— Dimerospo- 



Perithecia superficial, globose, minute, ^o n i dTif e?Tscu^: 

 black, aggregated in botryose fashion, stro- After winter.' 

 mate; asci cyUndric, 8-spored; spores oblong, 2-celled, hyaline. 



The one species L. lonicerse Kze. forms dark coatings on honey- 

 suckle leaves in Europe, North Africa and Siberia but does little 

 or no harm. 



Zukalia Saccardo (p. 190) 



This genus is like MeUola except in its hyaline spores and in 

 its perithecium. 

 Z. stuhlmanniana is on seedling cocoanuts and other palms. 



Apiosporium Kunze (p. 190) 



Perithecia superficial, minute, globose to pyriform, membra- 

 nous or carbonous; asci ovate to clavate, 8-spored; spores 

 globose to oblong, hyaline; paraphyses none. Conidia=Torula, 

 Fumago, Chaetophoma, etc. 



Several forms are known to constitute sooty coatings on leaves 

 of woody plants, subsisting on insect secretions. The specific 

 limitations in the genus have not been satisfactorily worked out 

 owing to the comparative rarity of the ascigerous stages. 



A. salicinum. (Per^.) Kze. is common on leaves of many species 

 of woody plants. 



Perithecia brownish, gregarious, globoid-oblong, composed of 



