4 CIRCULAR XO. 131, BUREAU OF PLANT INDUSTRY. 



EndotJiia radicalis Tnississippiensis subsp. nov. — The writers are 

 giving this name tentatively to a plant of which only four collections 

 have thus far been seen. These were all found on dead chestnut 

 coppice in northern Mississippi. In morphological characters it does 

 not appear to differ appreciably from E. radicalis, but in cultures it 

 shows constant and easily recognized differences. In pycnospore 

 streak cultures on potato agar +6 or +7 Fuller's scale this variety 

 produces less aerial growth along the streak than E. parasitica. When 



5 or 6 days old the surface growth is xanthine orange by reflected 

 light. When 2 weeks old it shows the most marked characters, being 

 grenadine red by transmitted light and producing no spore masses. 

 On corn meal the color of the myceUum becomes orange chrome at 

 the end of a week and the pycnidia are larger and less numerous than 

 in E. 'parasitica. The perilla-purple color developed in this medium 

 by E. radicalis appears very tardily or not at all in cultures of this 

 variety. There Is no evidence yet that it is any more parasitic in 

 tendency than E. radicalis. More material and data are necessary to 

 determine satisfactorily its taxonomic status. 



Endothia gyrosa (Schw.) Fr. — Under this name we shall treat of the 

 fungus which Clinton ^ calls E. radicalis (Schw. ?) Farl. This species 

 is easily recognized in its ascospore stage by its long, narrow, usually 

 nonseptate ascospores, mostly measuring from 7 to 11 by 1.5 to 2.5 

 microns. A discussion of the identity of this species will be given in 

 a later publication. 



Since these organisms when found on dead plants are not easily 

 distinguished from EndotJiia parasitica by macroscopic characters in 

 the field, nor always with certainty from microscopic studies, espe- 

 cially when only the pycnidial fructifications are found, it is desir- 

 able to have some other certain means of diagnosis in case of doubt. 

 With this end in view the cultural characters and reactions of the 

 organisms have been studied on various culture media. Over 2,000 

 cultures have been studied, including 19 different collections of E. 

 parasitica selected from 100 or more, mostly from Castanea species, 

 and a few from Quercus, ranging from New Hampshire to southern 

 Virginia, 24 European collections of E. radicalis on Castanea sativa 

 from Italy and Switzerland, and 54 American specimens taken from 

 over 100 collections on Quercus species and Castanea dentata, rang- 

 ing from southeastern Pennsylvania and Ohio to South Carolina 

 and Alabama; also 4 collections of the Mississippi form on Castanea 

 dentata from northern Mississippi and .34 collections of E. gyrosa 

 selected from 140 on Quercus species, Liquidambar, Fagus, and 

 Castanea dentata from Connecticut and ]\Iicliigan to Florida and 

 Texas. 



'Clinton, G. P. Chestnut-bark dLscase. Connecticut Agricultural Experiment Station. Annual 

 Report, 191?, pt. 5. p. 422, 1913. 



[Cir. 1.31J 



