416 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 Rep. N. Y. State Mus., p. 80. 



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



The appendages, from their length and manner of branch- 

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

 colored, and the perithecia are smaller and more delicate. 



2. Appendages Jiya/inc or nearly so. 



M. diffusa, C. & P. 



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



Usually epiphyllous. Perithecia scattered, 100-120 ^, dark, 

 opaque, reticulations rather obscure, 10-15 p; 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 u : 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. t)5. 



On Desmodium CUSpidatum: do Daviess, Sept. 20, ()(»tl; 

 Champaign, Sept. is, 6617, Oct. 25, 6599. Desmodium Gana- 

 dense: Lee, Sept. 12, 5793; Stephenson, Sept. L3, 5807, Sept. 



21, 6073; do Daviess, Sept. L8, 5970, 5972, 6001; Ogle, Sept, 



22, 6089. Desmodium paniculatum: do Daviess, Sept, L8,5973, 

 Desmodium sps.: Union (Earle). Li'si><></r:<< <'</i>it<t(<< : 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 t he appendages are usually 2 2. 1 , times the diameter of the 

 perithecium; but on Phaseolus, some of them are 3iJ times 



