19 



Hypophyllous. Mycelium usually dense, forming irregular, 

 whitish spots or patches. Perithecia scattered, flattened or depressed 

 aliove, large, 225-280 u: appendages very numerous, 250-300 or 

 more, about half as long as the diameter of the peritheciuin. at first 

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

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

 large, about 17 x 27 tjt, nearly filling the ascus. 



On Celtis occidental is, Carolina (Ravenel), Mississippi (Tracy), 

 South America (Spegazzini). Apparently not abundant. 



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



Uncinula polychata, B. & C. Grev. IV, p. 159 (No. 993). 

 Pleochczta Cnrtisii, Sacc. and Spegf. 1. c. 



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

 thecia scattered, usually not more than 2-3 on a leaf, 150-200 //. : 

 appendages 25-28, simple, colorless. Y<TV slender, about 300x2-3 // : 

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

 dric-clavate, 4-spored. Sporidia colorlc . -imple. elliptical, oblong. 

 20x10 //. 



On leaves of Celtis occidentalis, Carolina. 



I . genicnlata, Gerard, Bull. Torr. Bot, Club, IV, p. 48. 



Epiphyllous. Mycelium thin, in definite spots or overspreading 

 the leaf. Perithecia scattered, usually lew, 90-120 it; appendage? 

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

 to twice the diameter of the peritheciuin in length, about 1J times 

 spirally coiled at the apex. Asci 6-8. Sporidia 46, about 14-20 /,< 

 Ions'. 



t_ 



On J/o/w.s rubrfi. rare or missed bv collectors. Xew York, 







Illinois (Pammel). 



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, Lk. Spec. Plant. VI, I, p. 117. 



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



L'ncinulci adioica, L,ev. Ann. Sci. Nat. Ser. Ill, Tome XV. 



l')icinula leucidenta, Howe, Trans. Albany Inst. VII, quoted in Amer. Nat. VII, 



P- 58. 



I'ncinula hcliciformis, Howe, Torr. Bull. V, p. 4. 

 L'ncinula Salicis, DC. Winter, Die Pilze, II, p. 40. 



Amphigenous. Mycelium abundant, persistent. Perithecia usually 

 large, 100-160 /A 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 



