ASPERGILLUS FUMIGATUS, A. NIDULANS, A. TERREUS 
N. SP. AND THEIR ALLIES* 
Charles Thom and Margaret B. Church 
Wehmer in one of his keys based upon single characters has 
brought together some short-stalked species of Aspergillus^ without 
indicating that the number of correlated characters found might 
justify more than an arbitrary grouping. He calls this section 
" Schwachwuchsige " or weak growers in spite of the fact that its 
best-known members, A. fumigatus and A. nidulans, are cosmopolitan 
and aggressive forms. If we substitute for this designation the 
designation short-stalked Aspergilli with calyptriform heads, we will 
bring together two green series typified by A. fumigatus and A. 
nidulans, and an ill-defined group of species whose colors are given 
as avellaneus, fawn, cinnamon, or reddish brown but never green. 
In long-continued culture of certain of the green and yellow-green 
forms within this group, the color changes in the conidial masses have 
been followed. Greens, blue greens, and yellow greens may run into 
each other ; any of them may develop dark shades in age which mask 
the original color, but they do not transform into avellaneus or related 
colors. Similarly the rosy or cinnamon series do not show any trace 
of green. 
Many cultures of members of this general group have been brought 
together. Some of these forms are readily aligned with species de- 
scribed in the literature. Others diverge more or less widely. Some 
of these are either entirely undescribed or so inadequately described 
as to make identification hopeless. All of these forms have stalks 
short, rarely exceeding 500 jx in length, and heads usually small in 
diameter with conidial masses in columns (calyptriform), not as 
separate chains or masses of chains radiating from the vesicle (radiate). 
* Published by permission of the Secretary of Agriculture. 
1 Wehmer, C, Die Pilzgattung Aspergillus in morphologischer, physiologischer, 
und systematischer Beziehung unter besonderer Beriicksichtigung der Mittel- 
europaeischen Species. Mem. Soc. Phys. Hist. Nat. Geneve 33^: 1-156. Pis. 1-5. 
1901. This paper is commonly referred to as Wehmer, Monograph (Monogr.). 
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