Davis—Notes on Parasitic Fungi in Wisconsin — XI. 291 
deficiency is considerable the pressure of the mesophyll tends to 
flatten the remainder and produce an acervular structure. This 
is more likely to happen in the thinner leaf of Fraxinus nigra. In 
the normal pycnidium the length of the sporule may equal the 
radius of the pycnidial cavity but in the acervular condition it is 
limited to the distance from the hymenium to the epidermis. 
Fig. 2. Diagram to illustrate influence of position of pycnidium with 
reference to epidermis on its development. Drawn by E. Dopp Jr., from a 
sketch by the author. 
I have seen no specimen that corresponds to the description of 
Cylindrosporium fraxini (E. & K.) E. & E. (Journ. Mycol. 1:128), 
Cercospora fraxini E. & K. loc. cit. 1:2). As noted above Fungi 
Columbiani 1526 issued under this name appears to belong to the 
group of forms considered above. 
Of the parasite of Fraxinus or eg ana of which Fungi Columbiani 
4415, 4719, and 4816, issued as Cylindrosporium fraxini (E. & K.) 
E. & E., are examples, I have seen no description. It causes red¬ 
dish brown spots with a paler margin of more or less circular out¬ 
line quite variable in size and sometimes confluent. The acervuli 
are epiphyllous, subcuticular, and soon erumpent. The sporules 
are cylindrical, usually curved or undulate, becoming about 4-sep- 
tulate, mostly 40-60x2-3jn. The epiphyllous, subcuticular habit 
especially seems to remove this from the forms considered above. 
As the range of species of Uredinales in North American Flora 
Vol. 7 is based on specimens in the Arthur herbarium there are 
sometimes considerable restrictions. For instance the range of 
Puccinia aletridis B. & C. (Dicaeoma (?) aletridis (B. & C.) 
Kuntze) is given as ^‘The states bordering the Atlantic Ocean and 
Gulf of Mexico from Massachusetts to Texas”. Its occurrence in 
northern Indiana was recorded by Burrill {Parasitic Fungi of Illi¬ 
nois pt. 1, p. 195) and in Wisconsin by Trelease {Preliminary List 
of Wisconsin Parasitic Fungi, p. 25). It has been collected in Wis¬ 
consin as recently as 1922. 
