Uncinula 111 



100// in diameter, appendages 20 ji wide across the apex, and from 

 3 to 6 asci. In the American examples the appendages vary from 

 10 to 35 in number, and are usually about 20, and are from i to 2, 

 or even 2^ times the diameter of the perithecium ; in the Japanese 

 example on ApJianantJic the appendages vary from 7 to 18, and are 

 usually about 12, and equal or slightly exceed the diameter of the 

 perithecium. They are also, as a rule, slightly wider at the base 

 than is usually the case in American U. Clintonii. 



Both the Japanese specimens agree with U. Clintonii in the small 

 subglobose asci, and spores distinctly larger than those of U. 

 prunastri, and it seems best therefore, so long as U. Clintonii and 

 U. prunastri are maintained as distinct species to regard the Japa- 

 nese plants as belonging to the former species. It may be pointed 

 out that these forms on Zelkova and Aphananthe differ just as 

 slightly from one another, as either of them does from typical U. 

 Clt ntonii. 



1 1 . U. GENicuLATA Gerard 



U. geniculata Gerard, Bull. Torr. Club, 4: 48. 1873; Sacc. 

 Syll. Fung. 1:8. 1882 ; Burr. ; Ell. & Everh. N. Amer. Pyren. 



19. 1892. 



Exsicc. : Rab.-Wint-Pazsch. Fung. Eur. 3955; * Seym. & 



Earle, Econ. Fung. 152. 



Epiphyllous; mycelium thin, arachnoid, forming definite 

 patches, or more or less effused, sometimes evanescent ; perithecia 

 subgregarious on the patches, or scattered, small, 90-i20/.£ in di- 

 ameter, usually about 100 M, globose-depressed, cells rather irreg- 

 ular, 10-15 // wide ; appendages 24-46, i^ to twice the diameter 

 of the perithecium, delicate, 3-4 // wide, some usually abruptly 

 bent or geniculate, simple, colorless, aseptate, thin-wailed, smooth 

 or minutely rough at base, apex simply uncinate: asci 5-8, 

 broadly ovate, very shortly stalked, 48-56 x 34-3^ « : spores 

 4-6, 22 X 12 ti. 



Host. — Morns rubra. 



Distribution.— ^OKTK America: United States— New York 



(144), Indiana, Alabama, Illinois, Missouri, Kansas. 



This species approaches slightly certain forms of U. salicis, but 

 is distinct in the smaller perithecia, with fewer delicate narrower 

 appendages, which are not enlarged but usually slightly attenu- 

 ated upwards. In U. salicis the appendages are, as a rule, much 



