THE FUNGI WHICH CAUSE PLANT DISEASE 187 



asci 4-9, 48-60. X 28-30 fi, ovate-oblong with a very short stalk; 

 spores 3-6, usually 4, 18-22 x 9-11. 



Hosts: Desmodium, Glycyrrhiza, Lespedeza, Phaseolus, Sym- 

 phoricarpos. 



M. betas Vanha ^^^ has recently been described as a species in- 

 jurious to the beet. It is said to resemble E. polygoni but that 

 cross inoculation between the beet and clover could not be made. 



M. ferruginea Erik, is found on cultivated Verbenas '^^ in 

 Sweden. 



M. euphorbiae (Pk.) B. & C. occurs on various hosts in America 

 and Asia, including Astragalus, Colutea, Cuphea and Euphorbia. 

 Its only economic importance is as the cause of a disease of the 

 roselle and cowpea ^^' on which it is very common. 



Amphigenous; mycelium usually subgeniculate; perithecia gre- 

 garious in floccose patches or scattered, 85-145 fi, rarely 180 /t, 

 cells 10-15 n; appendages 7-28, usually narrow, more or less 

 fiexuose and nodose, 2.5 to 8 times the diameter of the perithecium, 

 colorless above, 3 to 4-times dichotomously branched, branching 

 irregular and lax; asci 4-13, rarely up to 26, ovate or ovate-oblong, 

 short-stalked, 48-66 x 26-35 p.; spores usually 4, rarely 3, 5 or 6, 

 16-21 X 10-12 /i. 



Phyllactinia L6veill6 (p. 175) 



Perithecia large, globose-depressed to lenticular; asci many, 2 

 or 3-spored; appendages equatorial, rigid, acicular, with a bul- 

 bous base; apex of perithecium with a mass of densely crowded 

 branched outgrowths. 



Typical epidermal haustoria are not produced but the mycelium 

 sends special branches through the stomata into the intercellular 

 spaces of the leaf."^ These branches attain some length and con- 

 stitute a limited internal mycelium, a character that is considered 

 by some as of sufficient importance to set the genus apart in a 

 separate family. The internal mycelium gives off haustoria which 

 penetrate cells of the mesophyll. The appendages exhibit strik- 

 ing hygroscopic movements and aid in dissemination. 



Only one species is recognized by Salmon. 



P. corylea (Pers.) Karst. 



Hypophyllous or rarely amphigenous; myceUum evanescent 



