286 FUNGUS-FLORA. 



Geotrichum candidum. Link. (fig. 17, p. 313.) 

 Tufts i)ulvinate, white, rather powdery; sterile hj-phae 



creeping, somewhat continuous : fertile ascending, short ; 



conidia cylindrical, truncate at both ends, 5-10 X 4, hyaline. 

 Geotrichum candidum. Link, Ohs., i. p. 15; Sacc, SylL, 



n. 183. 



On the naked ground, also on damp, rotten paper, 



hones, &c. 



Geotrichum roseum. Grove. 



Hyphae creeping, white, interwoven ; conidia pale rose- 

 coloured, concatenate, shortly cylindrical, ends truncate, 

 16-30 X 9-10 fjL or sometimes longer. 



Geotriclium roseum. Grove, Journ. Bot., tab. 206, f. 8 ; 

 Sacc, Syll., iv. n. 185. 



Forming dense small, round or ohlong rosy spots at the 

 base of a species of Juncus. 



OIDIUM. Link (emended), (fig. 8, p. 313.) 



Growing on living plants. Mycelium creeping, conidio- 

 phores erect, sub-sinijDle ; chains of .conidia soon breaking 

 up ; conidia rather large, elliptical, colourless or coloured. 



Oidium, Link, emended by Saccardo, Mich., ii. p. 15; 

 Sacc, Syll., 40. 



Develoj)ing on living plants, chiefly on the leaves. Many 

 species have been proved to be the conidial condition of 

 ascigerons fungi belonging to the Perisjwriaceae. 



1. On Dicotiilcdons. 



Oidium erysiphoides. Fr. 



Broadty effased, indeterminate, white; tufts conspicuous, 

 rosy-white ; hyphae almost erect, very slender ; conidia 

 ovate, oblong, pellucid, internally granular, 30-45 X 13-20 ft. 



Oidium erysiplioides, Fries, Svst. Mycol., iii. p. 432 ; Sacc, 

 SylL, iv. n. 180. 



On living leaves of various plants. The conidial phase of 

 a species of Erysiplie. 



Oidium leucoconium. Desra. (fig. 8, p. 313.) 

 Tufts broadly effused, white ; hyphae creeping with short, 

 erect, fertile branchlets ; conidia elliptical, 20-30 x 13-16 /x. 



