Poritliot'ia few or nuiiioroiis, immersed in the mycelium, small 75-85 /^, 

 glol)08e orsiiltjtyriform; appendaf^es of two kinds, in [)art rudimontary, 

 lloccose, deo|»Iy colored, attached in a broad tuft to the smaller end 

 of the i)yriform pcritliecium, the otiioi's strongly developed, rigid, 

 straiglit or curved, continuous or sej)tate, simple or rarely forked at 

 the extremity, deej)ly coIohmI at base, becoming j)alo outwardly, 

 attaclied in a loose cluster op|)osite the rudimentary ones, 2-5 times 

 the diameter of the j)erithccium. Ascusoval to std)globose. Sporidia 

 8, 20-30 fi long. 



On upjicr jtai'ts of tlie twigs of /*?//•«« Maltis, especially in nurs- 

 eries of young trees, and ujton the suckers from old ones. Not appar- 

 ently very frecpient but exceedingly al)undant at times, Mississippi 

 Valley, and probably eastward. 



This exceedingly interesting species has not been well separated 

 from PodoHphmni Oj'.yncdnthm which occui-s on the same host and to 

 casual observation has nuTbh the same ai)pearance. In our species the 

 tii)s of the I'trge ai)pendages are occasionally forked (once or even 

 slightly twice), which again may have been confusing. But these 

 vagiu', stiff branches are totally unlike the dichotomous divisions of 

 PodoupJuvra, and otliei'wise the s})ecies are very distinct. The tuft 

 of short, interwoven, rudimentary ai)})eiidages, like a dense cluster of 

 short loots, is a very characteristic mai-k. 



There is still some doubt as to the name. Evidently Enjsiphe 

 JTdJf, Moug. usuallv given as a varietv of ErysipJie adn?ica, (Fi'lc^ 

 Syst. Myc. Ill, p. '245, Wallr. P^lora" Germ. IV, p. 755, A'c.) is a 

 different thing, but Duby's description (Botanicon Gallicum I, j). 869) 

 so Ihr as it goes, is sufficiently correct for our species. Enjslphe 

 Mall, Duby, in Roumeguere's Fungi Galilei Exsiccati is a Sphcu- 

 I'otheva, and seems to be the same as our plant, though the specimen 

 examined was insufficient foi' satisfactory comparison. It is moreover 

 scarcely possible that this host should have a solely American parasite 

 of this kind upon it, hence the preference given in the nomenclature. 



S. iiiors-iivsp, (Soliw.) 



Erysiphe mors-xivce, Schw. Syn. N. Am. 2494. 

 Sphtziotlu'ca mors-xiva:^ B. & C. Grevillea IV, p. 158. 



Mycelium abundant, at first white, becoming dark brown, densely 

 covering the leaves, stems and fruit. Perithecia most abundant on 

 the stems and fruit, densely aggregated, imbedded in the thick, felted 

 mycelium, varialde in size, 19-120 //, dark brown, reticulations 

 obscure; a])])endages short, delicate, hyaline or slightly colored, 

 interwoven with and overrun by the dense mycelium. Ascus broadly 

 elliptical, S-sjwred, both ascus and sporidia smaller than in 8. pan- 

 nom. 



