90, A Monograph of, the Erysiphaceae 



At first sight, the present variety appears to much resemble. 

 U. geniculata, but on closer comparison it is seen that in the latter 

 species the appendages are always distinctly narrower, not enlarged 

 upwards and more delicate. - ' 



I - k 



Rarely, the appendages of. the present plant are more or less 

 regularly flexuose and not angularly bent ; there i? then some 

 slight approach towards 77. fiexiwsa, which differs in the shorter 

 appendages, 8-spored asci, etc. Very rarely, and perhaps abnor- 

 mally, a single appendage is found branched at the apex (figs. y6^ 



77)' ^ ' ^_ ' " . ■ 



The OTily example sent on Almis ijicana differs from those on 



A. Japojiica in the mycelium forming definite spots on the upper 



surface of the leaf The perithecia are seated on these, and as 



a rule, although not invariably, are larger. 



r ■ ^ I 



, - 2. U. ACERLS (DC.) Sacc.' [Fig. %j^^ ■ 



Miicor Erysiphe Lirin. Sp. PL 2 ; Ii86 (partini). 1753. 



Erysiplie accris \)Q.^ Syn. PI. Fl/ Gall. 57, 1806; Duby,' 

 Bot. Gall. 2 : 870. 1830; Tul. Sel. Fung. Carp, i : igy. pL 2. 

 f. 2, J, i86r ; de Bary, Beitr. Morph. Phys. Pilz. i: § xiii., 



52. 1870. 



E. variuui Fr. Obs. Myc. (partim) l : 206. 181 5 ; 2: 366. 



i8i8. 



AlphitomorpJia biconiis Wallr. Berl. Ges. Nat. Freund. Verb. 

 i: 38. 1819; Wallr. Ann. Wett. Ges. 4 : 235. 1819; Wallr. 

 FL Crypt. Ger. 2: 755. 1833. 



Erysibc acerls DC, Gray, Nat. Am Brit. PL I : 5S9. 182 1. 



E. biconiis {tice?'iiui) Lk.; Willd. Sp, PL 6 : 112, 1824; 

 Rabenh. Krypt. FL Deutschl. i: 235, 1844. 



Erysiphe biconiis Fr. Syst. Alyc. 3: 244 (partim). 1 829; 

 Berk.; Sm. Engl. Fl. 5: 327. 1836; Corda, Icon. Fung. 2 : 



2%. pi. 13. f. TOO. 1838. 



Uncimda biconiis Lev. Ann. Sci. Nat. IIL 15 : 153. //. 7. /. 

 // (partim). 185 I ; Cooke, Micr. Fung. 219.//. //. /. 223-228. 



I 



1865 ; Cooke, Handb. Brit. Fung. 2 : 647. 1871. 



U. aceris (DC.) Sacc. SylL Fung. 1:8. 1882; Wint. in 

 Rabenh. Krypt FT Deutschl. l" : 4I. 1884; Schroet. in Cohn*s 

 Crypt, FL Schles. 3: 246. 1893; Jacz. Bull. THerb. Boiss. 4: 



