FusARiA OF Potatoes 



187 



prominently pedicellate, typically much arcuate, 5-septate, 49.2 x 4 

 (42-54x3.6-4.2)^1, also often from 3- to 7-septate; single on aerial 

 conidiophores and in from small to medium (up to 1.5 millimeters in 

 d'.ameter) sporodochia, the latter sometimes converging into pseudo- 

 plonnotes; intercalary chlamydospores in mycelial threads typically 

 present, though not numerous, and single or only in small clusters of from 

 two to four cells; aerial mycelium usually well developed, uniform, white 

 at first, then, on substrata poor in glucose, of different tints of pink with 

 the substratum of a pomegranate color of different density; on potato 

 agar rich in glucose, color as shown in Plate ii, figures 7 and 8. 



Fig. 23. — Fusarium arcuosporum. a, Sporodochial conidia, b, conidiophore, from 20-days- 

 old culture on hard lima-hean agar with 2 per cent glucose: c, conidia from small aerial sporo- 

 dochium from 4-9-days-old culture on whole steamed potato tuber; d, typical co7iidimn {the long 

 one) and abnormal pseudopionnotal conidium from 11 -days-old hard potato agar; e, aerial 

 conidia, f, chlamydospores, g, conidiophores, from 75-days-old culture on red raspberry cane, 

 plug; H, pseudopionnotal conidia, i, conidiophores, from 12-days-old culture on slightly acidified 

 hard potato agar; j, conidiophore, K, chlamydospores, l, conidial ball, M, conidiophores, frovi 

 aerial mycelium from 75-days-old culture on red raspberry cane plug; N, chlamydospores from 

 173-days-old culture on corn agar; o, peculiarly branched, p, normal, pseudopionnotal conidia 

 from H-days-old culture on hard lima-bean agar; q, conidia from aerial sporodochium of 107- 

 days-old culture on potato stem plug; n, conidia from 109-days-old culture on rye straw; s, typical 

 sporodochial conidium from 24-days-old culture on potato tuber plug; T, chlamydospores from 

 109-days-old culture on rye straw 



Hab. On rotted tubers of Solanum tuber osu7n, in association with 

 F. anguioides, Castile, New York. 



