262 
Journal of Agricultural Research 
Vol. II, No. 4 
C. SECTION GIBBOSUM 
[Species in section Gibbosum are Fusarium gibbosum App. and Wollenw., F.faleaiutn Av>p. and Wollenw., 
F . sclcrotium Wollenw., F. caudatum, n. sp., F. caudatum , var. voluium, n. var.] 
4. Fusarium caudatum, n. sp. 
Diagnosis.—Conidia with a tail or whiplike prolongated apical cell and a pedicellate 
base with well-marked heel, ochreous to salmon colored in mass, formed in sporodochia 
and in pionnotes; 5-septate conidia averaging 40 to So by 3 to 4.5/i, lower and higher 
Septations more rarely occur. Brown chlamydospores, 7 to 14 fi in diameter, as a rule 
intercalated in chains or clusters, but frequently single if formed from the content of 
the cells of conidia under poor conditions, such as in water. 
Habitat.—On partly decayed stored sweet potatoes (Ipomoea batatas) from Clemson 
College, S. C. (Collected by Harter and Field.) 
This species differs mainly from Fusarium gibbosum in having more slender conidia, 
with a prolonged apical cell and a less pronounced hyperbolic curve of the dorsal side. 
The hyperbolic curvature of the conidia, when seen in side view, is not 
as pronounced with Fusarium caudatum (PL XVI, fig. M) as it is with 
F. gibbosum . This is due to the more slender form of F. caudatum. All 
the other characters point at once to the section Gibbosum. The long 
and whiplike projection of the apical cell, the pedicellate base, with the 
long foot adorned by a heel (Pl. XVI, fig. M), the clusters and chains of 
chlamydospores, the formation of intra- and extra-cellular conidio- 
chlamydospores (see PL XVI, fig. A, 4) in very moist culture conditions— 
all these are invariably connected with species of this section, such as 
F. gibbosum , F. sclerotium i and F. falcatum. The morphology of the first 
species is referred to; this,is completely described by Appel and Wol- 
lenweber (1910). F. caudatum differs in having a more slender form, 
being longer and narrower when compared with F. gibbosum (30 to 60 by 
4 to 5.25/1). The tail or whiplike prolonged apical cell is a special char¬ 
acter of this fungus, which also forms an abundant pionnotes when single 
5-septate conidia are transferred to steamed potato tuber. 
A similar but higher septate species of the same section occurs on 
potato stems, but has more septa and conidia up to ioofx in length. This 
and a strain from pine seedlings require more study before a definite 
determination can be made. 
However, a variety of Fusarium caudatum with more curved and 
smaller conidia is added here and named F. caudatum , var. voluium 
(PL XVI, fig. P). Both forms are isolated only from sweet potatoes. 
Their frequency and distribution remain uncertain. 
Comparative studies on chlamydospores show that the section Gib¬ 
bosum deserves a higher rank in the genus than the section Discolor, 
although both show a remarkable development in the production of this 
hibernating form. Clusters and chains of chlamydospores are produced 
in species of both sections. They may even predominate if water has 
been liberally furnished. The simplest form of a chlamydospore is a 
globose or pyriform cell with a thick membrane consisting of at least two 
