FusARiA OF Potatoes 261 



text fig. 6. 1910. Wollenweber, H. W., Phytopath. 3:31, 44, 45, Fig. Ic. 

 1913. 



Microconidia of larger size than those of other species of section Mar- 

 tiella, 0-septate, about 16 x 4.7/x. Macroconidia, for the largest part, of 

 an even diameter or somewhat broader toward the base, only slightly 

 curved near, and more or less rounded at, the apex, never apically con- 

 stricted, mostly apedicellate or with ventrally depressed basal cell, mostly 

 3-septate, 33.3x5 (30-36 x 4.5-5.4) m; aerial mycelium usually medium 



Fig. 48. — Fusarium coeruleum. a, Pseudopionnotal conidia, b, conidiophore, from 8-days- 

 old colony in petri dish on hard potato agar; c, chlamydospores, d, coremium-like form of mycelial 

 growth with conidiophores, e, pseudopionnotal conidia, from 35-days-old culture on potato tuber 

 plug; F, conidiophore from 62-days-old culture on rye straw; g, conidia (some with chlamydo- 

 spores), H, conidiophore {magnified 250 times), from S^-days-old culture on rye straw; i, conidia 

 from small sporodochium, j, conidiophore, from 79-days-old culture on red raspberry cane plug; k, 

 chlamydospores, l, pseudopionnotal conidia, from 22-days-old culture on hard potato agar, a, 

 B, F, G, and H are from strains isolated from rotted potato tubers received from American sources, 

 the remainder are from the culture received from Dr. Wollenweber 



well developed, feltlike in age, of from white, bluish white, and olive-buff 

 to dusky slate violet, on potato agar rich in glucose, and to slate purple 

 on corn meal agar; substratum, on potato agar rich in glucose, from deep 

 hyssop violet to Indian lake, ocher-red, and, in older cultures, violet- 

 carmine; color of conidia from orchraceous orange, on strong acid agars, 

 to pale buff and mouse gray, or often blue, on neutral media. 



Hab. On rotted tubers of Solanum tuberosum, common in Europe and 



