July is, 1914 
Fusarium on Sweet Potato 
259 
Desmazieres gave in 1849 a short and incomplete description of this 
fungus, calling it Fusisporium incarnatum Roberge, following the designa¬ 
tion given by Roberge, the collector of the original material, which con¬ 
sisted of affected inflorescences of Tagetes erecta. In 1881 the fungus was 
transferred to Fusarium by Saccardo in Michelia; it also occurs in Sylloge 
Fungorum (Pis. XIII, fig. H , and XVI, fig. L). The best description of 
this cosmopolitan species is given by McAlpine (1899), who well illus¬ 
trated the conidia from a citrous stem. He found the fungus associated 
with Gibberella pulicaris in October, 1878, at Ardmona, Victoria, Australia. 
The present author, although basing this diagnosis on a strain from 
Ipomoea, has compared pure culture strains from a wide range of hosts. 
In looking over the flowers in ornamental gardens late in the summer, one 
can easily see the pink powder formed by this fungus on plants such as 
Aster, Iris, Dianthus, Campanula, and Tagetes. It occurs on stems and 
inflorescences and is not confined to ornamental plants, as proved by its 
presence on the dead stems and seed bolls of Hyoscyamus, a wild plant 
common in the United States. Determinations of strains from sweet 
potato showed its occurrence on the roots. In Germany dead stems of 
Lupinus are also inhabited by Fusarium incarnatum . Although the 
effect of this fungus on the living plant remains to be worked out, its 
cosmopolitan and ubiquitous nature seems fully established by these 
comparative morphologic studies. 
A relative of Fusarium incarnatum , which often has been found 
associated with Gloeosporium, occurs on the fruit of the banana. This 
Fusarium, F. semiiecium B. and Rav., has smaller conidia and in the 
average fewer septa than F, incarnatum. Inoculation experiments are 
desirable to throw further light on the simultaneous relations of these 
organisms. This species is different from that described from carnations 
by Clayton J. Wight (1912), because it develops neither a lemon-yellow 
nor a wine-red color on rice; it has no true chlamydospores, and the pecu¬ 
liar curvature of the conidia (Pis. XIII, fig. H , and XVI, fig. L) gives it a 
special place in the genus. 
Fusarium dianthi Prill, and Delacr. (Delacroix, 1901) also is not identical 
with our species. Its relation to diseases of Aster is also doubtful. 
Fusarium incarnatum is of morphologic interest because of the absence 
of sporodochia and pionnotes. Such species in general are less constant 
in form and septation than those with sporodochia, but successive trans¬ 
fers to fresh culture media, such as stems of legumes and tubers of potato, 
will establish sufficient constancy to justify the interpretation of the 
illustrated conidia (Pis. XIII, fig. H , and XVI, fig. L) as normal. F. 
incarnatum may be provisionally placed in the Discolor section until 
related species now under investigation require a separation, which may 
be accomplished either by establishing a subsection of Discolor for them 
