148 Bulletin 313 



ScLEROTiuM BATATicoLA Taub. — On tlie living roots of sweet pota- 

 toes. Causes the charcoal rot. Described by Taubenhaus as fol- 

 lows : "Sclerotia jet black, very minute ; exterior smooth, made up of 

 anastomosed black liyphae; interior light to dark brown, made up of 

 free thick-walled, cortical, hyphal cells ; sclerotia vary much in shape, 

 spherical, oval, oblong, elliptical, curved or even forked, varying in 

 size from 25 x 22.4 //, to 152 x 32 fi, abundant throughout the interior 

 root of the host. 



Parasitic on living roots of sweet potato, Ipomoea batatas. 



859. Mass of sclerotia, 2/3. 860. Single sclerotium attached to mycelium, 

 1/6. 861. Fusion of mycelia, 1/6. 862. Irregular cell formation in mycelia, 

 1/6. 863. Stages in formation of sclerotia, 1/6. 



