19 



Hypophyllous. Mycelium usually deuse, forming irregular, 

 whitish spots or patches. Perithecia scattered, flattened or depressed 

 above, large, 225-280 // ; appendages very numerous, 250-300 or 

 more, about half as long as the diameter of the perithecium, at first 

 clavate, then attenuate and once coiled at the apex, hyaline. Asci 

 numerous, 50 or more, about 27 x 80 p.. Sporidia 2, or rarely more, 

 large, about 17 x 27 /i, nearly filling the ascus. 



On Celtis occidentalism Carolina (Ravenel), Mississippi (Tracy), 

 South America (Spegazzini). Apparently not abundant. 



U. confiisa, Massee, Grew XVII, p. 78. 



Uncinula polychtzta, B. & C. Grew IV, p. 159 (No. 993). 

 Pleochcsta Curtisii, Sacc. and Speg. 1. c. 



Hypophyllous. Mycelium very scanty, not forming spots. Peri- 

 thecia scattered, usually not more than 2-3 on a leaf, 150-200 i\ 

 appendages 25-28, simple, colorless, very slender, about 300x2-3 /*; 

 apices strongly involute, not at all thickened. Asci about 25, cylin- 

 dric-clavate, 4-spored. Sporidia colorless, simple, elliptical, oblong, 

 20x10 /jl. 



On leaves of Celtis occidentalis, Carolina. 



U. geniculata, Gerard, Bull. Torr. Bot. Club, IV, p. 48. 



Epiphyllous. Mycelium thin, in definite spots or overspreading 

 the leaf. Perithecia scattered, usually few, 90-120 //; appendages 

 15-30, hyaline, somewhat roughened, often geniculate, about once 

 to twice the diameter of the perithecium in length, about 1| times 

 spirally coiled at the apex. Asci 6-8. Sporidia 4-6, about 14-20 ti 

 long. 



On Moras rubra, rare or missed by collectors. New York, 

 Illinois (Pain mel ). 



U. Salicis, (DC.) (Plate 2) 



Erysiphe Salicis, DC. Flore Franc. II, p. 273. 



Erysiphe Populi, DC. Flore Franc. VI, p. 104. 



Alphitomorpha adunca, guttata, Wallr. Verh. Naturf. Freunde, I, pp. 37, 42. 



Erysibe adunca, obtusata, kk. Spec. Plant. VI, I, p. 117. 



Erysiphe adunca, Grev. Scott. Crypt. Flora, V, tab. 296. 



Uncinula adunca, Lev. Ann. Sci. Nat. Ser. Ill, Tome XV. 



Uncinula leuculenta, Howe, Trans. Albany Inst. VII, quoted in Amer. Nat. VII. 



p. 58. 

 Uncinula heliciformis , Howe, Torr. Bull. V, p. 4. 

 Uncinula Salicis, DC. Winter, Die Pilze, II, p. 40. 



Amphigenous. Mycelium abundant, persistent. Perithecia usually 

 large, 100-160 /i, wall tissue soft elastic, reticulations rather small 

 and indistinct ; appendages variable in number, usually very numerous, 

 hyaline, not much swollen at the tip, once to twice as long as the 



