178 



ASCOMYCETES. 





phyll in diseased spots, so that when dead and yellow, they 

 are still spotted with green. The conidia are oval, so also the 

 spores of which six to eight are found in each ascus. 



U. Tulasnei Fuck, produces 

 a white coating over the whole 

 leaf-surface of Acer 2)lata7ioides. 

 The conidia are spherical. 



U. circinata C. et Peck, is 

 found on species of Acer in 

 America. 



U. salicis D. C. (Britain and 

 U.S. America). This species 

 occurs on leaves of the willow, 

 and produces white spots or 

 thick coatings on one or both 

 surfaces. It is also found on 

 leaves of poplar and birch. 

 U. prunastri D. C. on Prmius spinosa (Britain). 

 U. Bivonae Lev. on Ulmus montana (U.S. America). 

 Also other American species. 



ml ti 1 . 

 luUsnt ) 



Phyllactinia. 



The spherical perithecia are flattened at the poles, and 

 enclose several asci containing two or three oval sulphur-yellow 

 spores. The appendages 



are sharp-pointed hairs 

 with swollen bases. 

 Phyllactinia suffulta 



Kebent. {I'lc. fjuttato 

 Wallr.) produces white 

 spots or coatings on the 

 leaves of many trees, e.(j. 

 beech, hornbeam, ash, 

 birch, hazel, oak, etc. 

 (Britain and U.S. 

 America). 



b'lo. 76.--Phi/llacliiila suffulta on Fagtis sylvatica. The 

 leaf is partially covered by a white mycelium, on which 

 the perithecia appear as black points, (v. Tubeuf del.) 



PERISPORIEAE. 



The Perisporieae include the following genera Tliielavia, Dimc- 

 rosporitcm, Mar/nusia, Cephalotheca, ZopficUa, Anixia, Eurotmm, 



