288 FUNGUS-FLORA. 



Oidium aceria, Kabach., Flora, 1854, p. 207 ; Sacc., Syll., 

 n. 207. 



On living leaves of Acer pseudoplatanus. 

 The conidial stage of Uncinula bicornis. 



Oidium mespilinum. Thum. 



Tufts lax, broadly eifused like a delicate cobweb on the 

 upper surface of the leaf, pure white ; hyphae short, simple, 

 without septa, hyaline; conidia obovately-elliptical, both 

 ends obtuse, simple, in chains of 2-3, hyaline or very pale 

 grey, 10 X 6 /*. 



Oidium mespilinum, Thum., Fungh. Litor, n. 249; Sacc., 

 Syll., n. 208, 



On living leaves of medlar (Mespilus germanica). 



Oidium pactolinum. Cooke. 



Thinly effused, golden-tawny ; hyphae very short, scarcely 

 conspicuous ; conidia subglobose, white in chains truncate at 

 the points of contact, at length when free globose, filled with 

 subgranular golden endochrome, 10 /A diameter. 



Odium pactolinum, Cooke, Sacc., Syll., iv. n. 209. 



On living jasmine leaves in a hothouse. 



Oidium balsamii. Mont. 



Forming a very delicate, white cobweb-like film, often 

 broadly eifused and minutely powdery from the conidia ; 

 sterile hyphae creeping, vaguely branched, sparingly septate, 

 slender; chains of conidia elongated, conidia elliptical and 

 truncate at both ends (barrel-shaped), hyaline, 15-22 x 

 8-10 u. 



Oidium balsamii, Mont., in B.& Br., Ann. Nat. Hist., n. 763 

 (name only). 



On living leaves of various species of mullein ( Verbascum). 



The above description is from Montague's specimen in 

 Berk. Herb., Kew. 



II. On Monocotyledons. 



Oidium monilioides. Link. 



Tufts broadly effused, ochraceous-white ; conidia forming 

 moniliform chains, elliptical, white or dirty white, hyaline, 

 25-30 X 8-10 p.. 



