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AMERICAN JOURNAL OF BOTANY 
[Vol. 8 
This organism in Czapek's solution agar is Kronberg's green without color 
in the substratum and without sclerotia. The following supplementary 
cultures are cited: no. 3557.9 from corn (isolated by Clawson) differs by the 
production of sclerotia, and yellow color in the substratum; no. 128, after 
many transfers identifiable with no. 108, produced a sclerotium — former 
resembling no. 3557.9; no. 2773 from Demerara is mignonette green, produces 
abundant sclerotia and yellow color in reverse. In general, sclerotium for- 
mation is found correlated with the production of yellow color in the sub- 
merged mycelium and with reduced intensity of green in the conidial area. 
^ Numerous strains with the same cultural characters have been obtained 
from many sources. The considerations leading to the retention of the 
name A. flavus for these forms are discussed later under ''nomenclature." 
A. ORYZAE Series 
Aspergillus oryzae has been generally accepted as a valid species. It 
is characterized as a group of varieties by Costantin and Lucet.^^ In the 
typical form represented by the cultures and descriptions of Wehmer, the 
species is readily separated from cosmopolitan forms of A. flavus. In the 
Oriental industries in which it has been long used, the separateness of this 
form is largely lost. It becomes, therefore, a gigantic race in a group in 
which other members possess the same habits, the same essentials of 
structure, but differ slightly in color and greatly in size. Growth upon 
different substrata produces great differences in the appearance of colo- 
nies. The fruiting stalks on Czapek's solution agar are commonly 2 to 
3 mm. in length, much longer on richly organic media, and are reported by 
Takahashi to attain a length of 20 to 30 mm. upon special rice media 
upon which the stalks of A. flavus reach a length of 5 m to 8 m. 
In contrast with A. flavus as already described, the following characteri- 
zation from cultures is proposed. 
A. oryzae (Ahlb.) Cohn. Colonies on Czapek's solution agar spreading 
broadly, pale greenish yellow (at its greenest about lime green to mignonette 
green. Ridgway, loc. cit. XXXI. 25'' YG-Y), with the green fading early 
to leave yellowish brown shades; sclerotia dark, produced occasionally, 
few and in clumps; mycelium and agar uncolored; stalks 2 to several milli- 
meters long, up to 20 to 25 in diameter; heads both large and small in the 
same culture, predominantly large, globose, and radiate rather than calyp- 
trate; sterigmata most commonly i -series, occasionally 2-series, primary 
sterigmata up to 8 to 12 by 5 secondary when present 7 to 10 by 3 m; 
conidia pyriform, colorless to very slightly yellow with walls so thickened 
as to leave circular, elongated, or winding pits^^ giving a rough or echinulate 
Costantin, J., and Lucet, L. Recherches sur quelques Aspergillus pathogenes. 
Ann. Sci. Nat. Bot. IX, 2: 119-171. 1905. 
^2 Takahashi, T. Preliminary note on the varieties of Aspergillus oryzae. Jour. Coll. 
Agr. Tokyo i : 137-140. 1909. 
12 "Areolate" of Johnston, loc. cit. 
