1 6 Raymond J. Pool 



On: Catalpa catalpa, C. spcciosa. 

 Lincoln, Wabash, Weeping Water. 



This variety is an extremely variable form. It occurs in the 

 east on species of Vaccinmm, and on Epigaea. Salmon writes in 

 regard to the form : " On the whole, the present plant appears 

 clearly marked off from typical M. alni by the long, flaccid ap- 

 pendages, and their usually more irregularly branched apex." 

 The perithecia are usually smaller than in M. alni. 



Microsphaera russellii Clinton. 



Amphigenous ; mycelium evanescent or sub-persistent, usually 

 inconspicuous; perithecia scattered, 70-1 i8/a in diameter, glo- 

 bose-depressed, cells small, 6-14^1 wide appendages 5-14, 3-7 

 times the diameter of the perithecium, flaccid septate, smooth, 

 colored nearly to the tip when mature, tip 2-4 times dichoto- 

 mously divided, branching very irregular and lax, primary 

 branches usually long and widely forking, tips of ultimate 

 branches not recurved ; asci 4-9, narrowly to broadly ovate, short- 

 pedicellate, 42-56X24-32^; spores 3-5, usually 4, 18-22 X 



lO-12/x. 



On: Oxalis corniculata, O. cymosa, O. stricta. 

 Crete, Lincoln, Naponee, Valentine, Weeping Water. 



Microsphaera diffusa Cook & Peck. 

 Microsphaera symphoricarpi Howe. 



Amphigenous ; mycelium persistent, thin and effused, sub-per- 

 sistent, or in some cases evanescent ; perithecia scattered or gre- 

 garious, globose-depressed, very variable in size, 55-126^ in 

 diameter, averaging 90-100^, cells 10—20,11 wide; appendages 

 very variable in number and length, 4-30, 1^—7 times the diam- 

 eter of the perithecium, smooth, aspetate, or 1-3-septate in the 

 lower half, colorless or pale brown toward the base, tip 3-5 times 

 dichotomously divided, branching diffuse and irregular, branches 

 of the higher orders sub-nodulose, tips of the ultimate branches 

 not recurved ; asci 4-9, 48-60 X 28-30^, ovate-oblong with a 

 very short pedicel; spores 3-6, usually 4, 18-22X9-11/*. 



On: Apios apios, Falcata comosa, Glycyrrhiza lepidota, Mei- 

 bomia canescens, M. canadense, M. grandiflorum, Sym- 

 phoricarpos occidentalis, S. symphoricarpos. 



74 



