110 C. D. Sherbakoff 



1. Color of conidia and mycelium, never of a plain gray or black color 

 but mostly of various brilliant hues. 



2. Conidia dorsiventral, 20 attenuate, pedicellate, 21 not appendiculate, 

 smooth, normally not constricted at the septa, distinctly three- (or more) 

 septate, 22 acrogenous, not in chains. 23 



3. Conidiophores with single to irregularly whorled branches, never 

 truly dichotomous nor of a strictly penicilla e or verticillate type. The 

 conidiophores, through many times repeated branching or also by growing 

 side by side with other conidiophores, typically give rise to macroscopically 

 observable, dense tufts of conidiophores covered more or less deeply 

 with a somewhat slimy mass of spores. Such fruiting bodies, tuberculate 

 in form (sporodochia), 24 may be with or without a plectenchymic (=pseudo- 

 parenchymic), flat or wartlike base, without any differentiated enclosure. 



4. Chlamydospores (endogenous, double-walled, resting bodies) terminal 

 and intercalary, or only intercalary, 25 or none, and produced both by 

 mycelium and by spores. 



5. Mycelium composed of hyphse which are always distinctly, but 

 not closely, septate, and irregularly, never dichotomously, branched, the 

 secondary branches usually thinner than the primary ones; protoplasmic 

 content of the mycelium for the greater part plainly present and usually 

 distinctly vacuolate. The rate of growth in artificial media, when com- 

 pared with the Fusarium-like organisms studied, is comparatively high. 



It must be added here, as a general remark to the characteristics of the 

 genus Fusarium given above, that in this case, as well as in any other 

 attempts at classification of natural phenomena, the boundaries laid 

 down for separation of one group of phenomena from all the rest have 

 only a relative value. Thus an organism may deviate 26 in a greater 

 or less degree in one or a few of the characters given above, and yet, so 



20 This term is used by Appel and Wollenweber (1910). 



21 This term is used by Wollenweber (1913 c). See his key on page 219 of reference cited. 



'" Fusaria-like organisms with one-septate conidia are rare. Two such organisms were isolated from 

 potatoes, and from over one hundred and sixty Fusaria recorded by Lindau (1908-1909:517-588) only 

 seven are definitely stated to have one-septate conidia; and of these seven at least two are undoubtedly 

 not Fusaria if the changes made in this genus by Wollenweber are considered. 



23 Microconidia may be produced in chains. This is true in case of certain Fusaria of corn and of 

 coniferous seedlings. (See Sheldon, J. L. A corn mold [Fusarium moniliforme n. sp.]. Nebraska Agr. 

 Exp. Sta. Kept. 17: 23-32, fig. 1. 1904.) 



24 The terminably used here is the same as that used by Wollenweber (1913 a : 24, footnote). 



25 The only Fusarium-like fungus isolated by the writer which has only terminal chlamydospores seems 

 not to be a typical Fusarium. (See F. cuneiforme, key and description.) 



26 Of course a true Fusarium, evidently, in no case can be of a plain gray or black color (in mycelium 

 and conidia as well), or have non-septateor cylindrical macroconidia with both ends rounded. (In regard 

 to the macro- and microconidia, see page 116.) Its conidia cannot be appendiculate nor its conidiophores 

 of a true verticillate or any other specifically peculiar type. 



