The Erysiphaceae cf Japan 



By Ernest S. Salmon 



(With Plate 26) 



During the past eighteen months I have received from Prof. 

 Kingo Miyabe, of the Sapporo Agricultural College, Japan, a large 

 and well-preserved collection of Japanese Erysiphaceae, numbering 

 200 specimens. Most of this material is mentioned in my " Mono- 

 graph of the Erysiphaceae " (3), but some of Professor Miyabe's 

 specimens arrived too late to be included. I have also received sub- 

 sequently 1 5 specimens from Prof. Shotaro Hori, of the Nishigahara 

 Exper. Station, Tokio. Further, two articles have lately appeared 

 dealing with Japanese mildews : one by H. & P. Sydow (1), in 

 which a supposed new species of Uncinula, U. Kusanoi, is described ; 

 the other by P. Hennings (2), in which " Phyllactinia sitffulta var. 

 moricola" and " MicrospJiaera Japonica" appear. Dr. Hennings 

 has very kindly sent me specimens of the two latter plants, and 

 included also with them specimens of three more species from 

 Japan under the Mss. names of Uncinula vcrniciferae, U. Sliiraiana 

 and Microspharca sambucicola. Dr. Hennings informed me that 

 the description of these species was already in the printer's hands, 

 and kindly gave me permission to mention them in this paper. 



To Prof. K. Miyabe and Prof. S. Hori I beg to express my 

 thanks for the valuable material (now in Kew Herbarium) sent by 

 them ; also to Mr. P. Sydow for a specimen of Uncinula Kusanoi. 

 Before giving a full list of the species (with their host-plants and 

 localities), known to me from Japan, a few remarks are necessary 

 on these lately published species. 



U. Kusanoi H. & P. Syd. (on Celtis Sinensis Pers.). Meguro pr. 

 Tokio (leg. Kusano), has perithecia from 80-110/./ in diameter, 

 cells of the outer wall 1 5-20 11 wide, appendages 10-20, usually 

 slightly exceeding the diameter of the perithecium, but varying 



from 1-1 y 2 times its diameter, often unequal in length on the same 



perithecium, simply uncinate at the thin-walled hyaline apex, be- 

 coming thick-walled, refractive, and often rough in the lower half, 



437 



