25« 
Journal of Agricultural Research 
Vol. II, No. 4 
(PI. XVI, fig. K). It is often isolated from Irish potato, especially from 
dry tubers affected with stem-end dry-rot. Sometimes it is associated 
with other organisms, but frequently seems to invade the tuber from the 
stolon before a cork layer has been formed to protect the stem end from 
outside infection. It has never produced the perfect stage. So far there 
is no sound basis for the supposition that it might be a strain of Hypo- 
myces which has lost the power of producing the perfect stage. The 
fungus occurs in Idaho, Oregon, and California, and probably in other 
Western States, and also in all of the New England States except the 
most northern. Its presence on the sweet potato suggests that it might 
require a higher optimum temperature than its related species, such as 
F. solani and F. martii. Inoculation experiments with strains from dif¬ 
ferent sources are desirable in order to throw more light on the relation¬ 
ship of the above-mentioned fungi and their comparative effect on their 
hosts. 1 
B, SECTION DISCOLOR 
[Species in this section are Fusarium discolor App. and Wollenw., F. discolor, var. suiphureum (Schleeht.) 
App. and Wollenw., F. culntorum (W. G. Sm.) Sacc. (Syn. F. ruhiginosum App. and Wollenw.), and 
F . incarnaium (Rob.) Sacc.l 
Fusarium incamatum (Rob.) Sacc. 
Fusisporium incarnaium Rob.; Desm., 1849, in Ann. Sci. Nat. Bot., s. 3, t. xi, p. 274. 
Fusarium ( Fusisporium ) incamatum (Desm.) Sacc., 1881, in Michelia, v. 2, no. 7, p. 296. 
Fusarium incarnaium (Desm.) Sacc., 1S86, Syll. Fung., v. 4, p. 712. 
Fusarium incarnaium Desm., ex Me Alp., 1899, Fung. Dis. Citr. Trees Austral., p. 106, fig. 141. 
Fusarium neglecium Jacz. (1912 in Bui. Soc. Mycol. France, t. 28, fasc. 4, p. 340-34S, fig. 4) is probably 
a synonym of F. incamatum . 
Diagnosis.—As a rule no sporodochia, no pionnotes, and no chlamydospores, but 
olive-brown plectenchymata of remarkable longevity are produced. The conidia, 
formed into a salmon-colored powder, are embedded in a floccose lanate mycelium of 
the same color. The fungus therefore resembles Fusarium trichothecioides Wollenw. in 
general appearance. Subnormal conidia are unicellular or septate, rounded at the 
ends, seldom pointed (PL XIII, fig. H, a). Normal conidia show characters of the 
section Discolor (PI. XVI, L), but are less curved and have mostly a conical (PL XIII, 
fig. H, b ), seldom a pedicellate base (Pl. XIII, fig. H, c). Slender conidia (Pl. XIII, 
fig. H, b) occasionally are seen but should not be confused with the section Elegans 
(compare F. orthoceras), Triseptate conidia measuring 20 to 25 by 3.5 to 4.5/1, and 
5-septate conidia, 30 to 50 by 3.75 to 5/*, may be predominant; 10-septate conidia 
occur more rarely. The conidiophores, mostly irregularly branched, show sometimes 
slightly verticillate ramifications. Chlamydospores are seldom present and are 
formed intercalated from hyphae, or occasionally from conidia. 
Habitat.—A cosmopolitan species. It is found in the stems, leaves, fruits, roots, 
and especially the inflorescences. It occurs rarely on monocotyledons, but has been 
obtained from Zea, Asparagus, and Iris. This species is confined mostly to dicotyle¬ 
dons and has been found on the following genera; Agrostemma, Dianthus, Brassica, 
Lupinus, Citrus, Ipomoea, Hyoscyamus, Solanum, Rhinanthus, Campanula, Aster, 
Tagetes, and Tussilago, It occurs in Europe, America, and Australia. 
1 Compare also the notes under F. orthoceras , a species connected with jelly end-rot, a serious trouble 
in California. 
