288 FUNGUS-FLORA. 



Oidium aceris, Eabacli., Flora, 1854, p. 207 ; Sacc, Syll., 

 n. 207. 



On living leaves of Acer j^seiidojjlatanus. 

 The conidial stage of Uncinula hicornis. 



Oidium mespilinum. Thiim. 



Tufts lax, broadly effused like a delicate cobweb on tbe 

 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 /x. 



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

 Sylh, 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 ju, 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 eifnsed and minutely j^owdery 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 

 8-1 0/x. 



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

 (name only). 



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



The above description is from Montague's specimen in 

 Berk. Herb., Kew. 



II. On Monocotijledons. 



Oidium m.onilioides. Link. 

 Tufts broadly effused, ochraceous-white ; conidia forming 

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

 25-30 X 8-10 /x. 



