Erysiphe 197 



Myc. Ven. 608, 904; Bri. & Cav. Fung. par. 263, 264; Rchm. 

 Ascoin. 396, 397; Cooke, Fung. Brit. Exsicc. 97^ 199, *200, 



466; ed. 2, 285, 287; Vize. Fung. Brit. 96, 199; Ayres. Myc. 

 Brit, "jy ; "^Erikss. Fung. Par. Scand. 37a, 146, 147a and b, 148b, 

 -^9* 339; *F1. Exsicc. Austr.-Hungar. 1173 ; Ell. & Everh. N. 

 Amer. Fung. 2916, 3006; Rav. Fung. Car. Exsicc. 69; ^Kneiff. 

 & Hartm. PI. Crypt. Bad. 13, 161 ; Wahrlich, Parasit. Pilz. 25, 26^ 

 27 (in Herb. Hort. Imp. Petropol.) ; Lib. PL Cr. Ard. 183 (m 

 Herb. Jarb. Bot. Bruxelles). 



Sub Erysiphe poly goni ; Rab. Fung. Eur. 1066, 1742, 191 7 ; 

 "^Desmaz. PI. Cr. Fr. ed. i, ser. i, 1108B, ed. 2, ser. i. 509A ; 

 *Krieg. Fung. Saxon. 826; Syd. Myc. March. 1 144; *Karst. 

 Fung. Fenn. 785; Berk. Brit. Fung. 202; Klotsch. Herb. Myc. 

 60 \ Westend. Herb. Crypt. Belg. 1058; Roumeg. Fung. Gall. 

 Exsicc. 2271 ; de Thiim. Fung, austr. 1250; Fckl. Fung. Rhen. 



670. * 



Sub E. taitrica ; Roumeg. Fung. Sel. Exsicc. 4564. 



Sub SphaerotJieca Castagnei; Rab. Fung. Eur. 1048, 1051, 



1916; de Thuem. Fung, austr. 441 ; Cooke, Fung. Brit. Exsicc. 



ed. 2, 591, 592; Sacc. Myc, Ven. 630. 



Sub Erysiphe galeopsidis ; Westend. Herb. Crj^pt, Belg. 409 ; 



Desmaz. PI. Cr. Fr. ser. i, 15 17. 



Amphigenous ; mycelium usually evanescent, sometimes per- 

 sistent and effused, usually white, rarely with a pinkish tinge ; 

 perithecia sub-globose or globose-depressed, often becoming con- 

 cave, gregarious or scattered, 80-140 p- in diameter, very rarely 

 140-180 //, cells variable In size, often very distinct, and 10—20 fi 

 wide, sometimes smaller, 10 /^ wide, and obscure; appendages 

 very variable, long or short, brown or sometimes colorless, usually 

 numerous, densely interwoven, vaguely branched, septate, light or 

 dark -brown throughout, and from 2-4 times the diameter of the 

 perithecium, but sometimes very few, and short or even rudi- 

 mentary^; asci usually numerous, about 10-15, but vaiying from 

 4-25, very rarely as many as '^6, variable in size and shape, from 

 narrowly ovate or subcylindrical to broadly ovate, or rarely sub- 

 globose, more or less stalked, 58-90 x 3^5o ,« ; spores 2, rarely 

 (and never uniformly) 3, 20-28 x 12-20 /i, usually about 24 x 



\4r [X- 



Hosts, Achillea Millefolium, A. Ptarmica, Actinomcns squar- 



rosa, Adenostylcs alpina (3), A, viridis, Ambrosia artemisifolia, A. 



