72 FUNGUS-FLORA. 



black patches 4-5 mm. thick and \-2 cm. across on the 

 upper surface of the leaves of the host plant, internally 

 white ; ascophores roundish or elongated, at length splitting 

 and exposing the yellowish disc; epithecium parenchy- 

 matous, cells minute, densely packed, dark olive; asci 

 clavate, apex narrowed, 8-spored ; spores needle-shaped, 

 pointed at both ends, curved, continuous, guttulate, hyaline, 

 65-95 X 1*5— 2*5 /x; paraphyses slender, apex wavy, hyaline 

 or with a brown tinge. 



Xyloma salicinam, Pers., Disp. Meth. Fung., p. 5, t. ii. 

 fig. 4. 



Xyloma umhonatum, Hoppe, Wahl. Flor. Lapp., p. 324. 



Spermogonia, Spermatia cylindrical, straight or slightly 

 curved, continuous, 5-6 jx long. 



Melasmia salicinum, Lev., Sel. Fung. Corp., iii. p. 119. 



On the upper surface of the leaves of various species 

 of willow. 



The spermatia are produced in the autumn, and the asci 

 appear in the same conceptacles the following spring on the 

 fallen leaves. 



Specimens examined from Fries' Scler. Suec, nos. 134 and 

 208, and Cooke, Fung. Brit., n. 461. 



Rhytisma andromedae. Fr., Syst., Myc, ii. p. 567 ; 

 Cke., Hclbk., p. 755 ; Eehm, Krypt.-Flora, Disc, p. 85 ; 

 Sacc, Syll., viii., n. 3087. 



Stroma externally shining black, forming irregular 

 patches, or frequently covering the entire upper surface of 

 the leaf; internally white, and composed of stout, thick- 

 walled interwoven hyphae ; ascophores elongated, often 

 wavy, at length gaping and exposing the pale disc ; asci 

 clavate, pointed above, 8-spored, spores long and narrowly 

 clavate, apex obtuse, lower half tapering and pointed, 

 straight or slightly curved, hyaline, continuous, guttulate, 

 50-60 X 5-7 /x, irregularly fasciculate ; parajDhyses slender, 

 about 2 [x thick, apex curled, hyaline. 



Xyloma andromedae, Pers., Syn. Fung., p. 104. 



On the upper surface of living leaves of Andromeda 

 polifolia. 



No secondary form of fruit is known, and the ascospores 

 are matured in spring on the fallen, decaying leaves. 



