Illinois State Laboratory of Natural History. 



Amphigenous; mycelium arachnoid, evanescent, appendages 8-18, 

 very long, flexuous, colored, paler toward the tips, which are simple or 

 one to three times divided; sporangia ovate, 4-8; spores 4, elliptical, 

 .0007-.0008in. long. Peck 26th Kep. N. Y. State Mus., p. 80. 



On Oxalis stricta: McLean, Oct. 7, 1827. 



The appendages, from their length and manner of branch- 

 ing, much resemble those of M. euphorbice, but they are strongly 

 colored, and the perithecia are smaller and more delicate. 



2. Appendages hyaline or nearly so. 

 M. diffusa, C. & P. 



(Erysiphei of the TJ. S., in Jour, of Bot. 1872.) 



Usually epiphyllous. Perithecia scattered, 100-120 /tt, dark, 

 opaque, reticulations rather obscure, 10-15 /*; appendages 15- 

 25, hyaline, or slightly tinted at base, 2-4 times as long 

 as the diameter of the perithecium, once to four or five times 

 irregularly or dichotomously branched, branches long and dif- 

 fusely spreading, not at all swollen or recurved; asci 4-7, ovate 

 pedicellate, rather small, 30-35 by 60-65 ^; spores 4-8, mostly 

 4-5. 



Mycelium thin, evanescent; conceptacles minute, globose, black ; 

 appendages numerous, eighteen to twenty-five, in length once or thrice 

 the diameter of the conceptacle, somewhat irregularly divided and 

 slightly nodulose at the tips; sporangia ovate, four to six, containing 

 four to six spores. Peck, 25th Rep. N. Y. State Mus., p. 95. 



On Desmodium cuspidatum: Jo Daviess, Sept. 20, 6041; 

 Champaign, Sept. 18, 6617, Oct. 25, 6599. Desmodium Cana- 

 dense: Lee, Sept. 12 ; 5793; Stephenson, Sept. 13, 5807, Sept. 



21, 6073; Jo Daviess, Sept. 18, 5970, 5972, 6001: Ogle, Sept. 



22, 6089. Desmodium paniculatum : Jo Daviess, Sept. 18, 5973. 

 Desmodium sps.: Union (Earle). Lespedeza capitata: Ogle, 

 Sept. 23, 6136. Lespedeza hirta: Union, Sept. 20 (Earle). 

 Phaseolus perennis: Union (Earle). 



This species seems to be well characterized by the long, lax 

 branching of the appendages. In Illinois specimens on Desmo- 

 dium the appendages are usually 2-2 J times the diameter of the 

 perithecium; but on Phaseolus, some of them are 3^ time% 



