Sphaerotheca 65 



certain species of the Erysiphaceae has led, I feel convinced, to 

 very numerous mistakes, and has made any compilation of a host- 

 index from pubHshed records alone utterly misleading. 



Further, not only are wrong host-plants for a certain species 

 thus given, but as a natural consequence our knowledge of the geo- 

 graphical distribution of the species in question becomes erroneous. 

 For instance, Winter (iii) records the occurrence of ** Sphacrc- 

 theca Casta^nci'' ''in foliis CnnirlntaccaruDi " from the island of St. 

 Thomas, Africa, an occurrence extremely interesting not only 

 geographically, but also climatically, as the island is on the 

 equator. In the present confusion it is impossible to say whether 

 the fungus was really '' S. Castagnci'' in a perithecial stage, or, 



r 



whether, as is more probable, it was not merely an Oidiiim which 

 had been referred to S. Castagnci in accordance with the usual 

 custom. 



The fungus recorded as *' 5, CastagneV on apples proves to 

 be Podosphaera leucotricha ; the records of the present species on 



ifolin 



2. S. PANNOSA (Wallr.) Lev. 



Alphitomorpha pannosa ^^^allr. Berl. Ges. Nat. Freund. Verh. 

 I : 43- 1819 ; Wallr. Fl. Crypt. Germ. 2 : ;6o. 1833. 



Eurotmm Rosarnm Grev. Scot. Crypt. FI. 3 : pL 164. /. 2. 

 1823, and 6: Synops. 7, 1826. 



Erysibe pannosa Schlecht. Fl. Berol. 2: 170. 1824; Lk.; 

 Willd. Sp. PI. 6 : 104. 1S24; Rabenh. Deutschl. Cr>-pt. Fl. I : 



F 



230. 1844. 



Erysiphe pannosa Fr. Syst. Myc. 3 : 236. 1829; Duby, Bot. 

 Gall. 2 : 869. 1830 ; Berk, in Sm. Engl. Fl. 5 : 325- i^S^ i Tul. 

 Sel. Fung. Carp, i : 208. //. 4../. 1-3 ■ 1861. 



Sphaerotheca pannosa Lev. Ann. Sci. Nat. III. 15: 13^- N- <^- 



f.8. 185 1 



//. //./ 217,218. 1865; 



Cooke, Handb. Brit. Fung. 2 : 645. 1871 ; Sacc. Syll. Fung, i : 

 3. 1882; Wint. Rabenh. Krypt. FI. Deutschl. i': 26. 1884; Karst. 

 Act. Soc. Faun. Fl. Fenn. 2 : 94. 1885 ; Burr. & Earle, Bull. 111. 

 State Lab. Nat. Hist. 2 : 3 98 (/.«'/////). 1887; Cooke, Handb. 

 Austral. Fung. 313.//. 25./. 2JQ. 1892 ; Burr.; EII. and Everh. 

 N. Amen Pyren. 6 {partim). 1S92 ; Schroet.; Cohn's Krypt. FL 



