FusARiA OF Potatoes 161 



On medium potato agar, culture ten days old : 

 Conidia: 3-septate, 9 per cent, about 45 x 3.3 (only two measured) 

 4-septate, 3 per cent 

 5-septate, 88 per cent, 58 x 3.5 (47-64 x 3.1-4)/x 



Average of the above measurements: 

 Conidia: 0- to 2-septate, absent or more or less rare 

 3-septate, 30 per cent, 38.4 x 3.4/i 

 4-septate, 19 per cent 

 5-septate, 51 per cent, 49.8 x 3.76^1 

 6-septate, absent to 1 per cent, 47.5 x 4.25ju 



16. Fusarium effusum n. sp. (Fig. 13; PI. vii, fig. 6) 



Conidia gradually pointed toward apex, distinctly but not prominently 

 pedicellate, typically 5-septate, 50x4.3 (44.5-57 x 3.9-4.5) ju, often 3- to 

 7-, seldom 1- to 2-septate; single or in indistinct pseudopionnotes and 

 in large (on oats, wheat, and the like, about | centimeter in diameter) 

 plectenchymic sporodochia; shape of conidia of nearly the same type, 

 in all stages and in mass, of salmon color and its tints; aerial mycelium 

 typically well developed, though on an agar may be resupinate, uniform, 

 without any differentiated tufts or strands, from white to cream and 

 tints of salmon color; substratum, on glucose agar, from chamois to 

 morocco red, and on glucose-free agar, from colorless to Eugenia red; 

 typical spore germination by straight, unbranched tubes (Fig, 13 j); 

 mycelium in young colony (Fig. 13 h) typically composed of nearly straight, 

 sparse in number, and more or less regular, branches. 



Hab. On dry tubers of Solanum tuberosum, Minnesota. 



Latin description. — Conidiis gradatim in apicem acutis, distincte sed 

 non insignite pedicellatis, typice 5-septatis, 50x4.3 (44.5-57 x 3.9-4.5) ac, 

 saepe 3-7-, raro 1-2-septatis; continuis vel in indistinctis pseudopionno- 

 tibus atque in magnis (in avena, tritico, etc., circa | cm. diam.) plecten- 

 chymicis sporodochiis; conidiis prope eodem in omnibus gradibus typo, 

 in totum " salmon-color " (R) ; aerio mycelio typice plene maturo, sed in 

 agare interdum resupinato, uniform!, sine uUis discretis cristis aut fibris, 

 ex albo ''cream color" (R) "salmon color" (R) vel simili colore; substrato 

 in agare glucoso e "chamois" (R) "morocco red" (R), in agare non 

 glucoso ex hyalino " Eugenia red" (R); sporis per rectos et non ramosos 

 cylindros typice germinatis (Fig. 13 j); mycelio in colonia juveni ex prope 

 rectis, sparsis, plus minusve regularibus ramis composito. 



