354 
OHIO BIOLOGICAL SURVEY 
THE ASCOMYCETES OF OHIO V* 
The Peliigeraceae. 
Leafy J. Corrington. 
Two genera, Peltigera and Nephroma, constitute the Peliigeraceae as 
represented in the flora of Ohio. The thallus is plainly foliose with the 
margins of the lobes usually ascending and is gray-green to brown in color. 
The lower surface is often conspicuously veined. There are two pronounced 
distinctions between the two genera. Peltigera has a well-developed 
cortex on the upper side of the thallus only (Fig. 1), while in Nephroma 
there is a well-developed cortex on both upper and lower sides (Fig. 2). 
The position of the apothecia constitutes another distinction. In both 
genera the apothecia are marginal or submarginal on the lobes, which 
are usually narrow and somewhat extended; but in Peltigera they are immer¬ 
sed in the upper surface, while in Nephroma they are imbedded in the lower 
surface. 
Peltigera furnishes seven species for Ohio, while only one species of 
Nephroma has thus far been found in the State. 
The algal hosts are usually Daciylococcus or Polycoccus, and both 
hosts are sometimes found in the sam.e thallus. The chains of cells are 
usually badly broken up, and the nature of the algal host is, therefore, 
difficult to distinguish. Other algae doubtless sometimes occur in the 
thalli of Peltigerae. 
Nephroma with cortex on both sides, is to be regarded higher than 
Peltigera, which has the cortex on the upper side only. The family is 
most closely related to the Stictaceae, from which family it is kept distinct 
on account of the absence of cyphellae and the difference in disposition of 
the apothecia. 
The collecting on which this paper is based was partly by Bruce Fink 
in connection with general collecting of fungi in Butler County and in 
collecting in Adams, Warren, Fairfleld, Preble, Ross, Highland, and Lake 
counties for the Ohio Biological Survey. However, a considerable amount 
of material found by other collectors and previously reported from Ohio 
was examined. Hence, the collecting for the Ohio Biological Survey added 
little to knowledge of the Pcltigeraceae of Ohio, except in way of addition to 
distribution in the State. 
Systematic Account 
PELTIGERACEAE 
Thallus foliose, with plectenchymatous cortex above (Fig.5), or both 
above and below (Fig. 2), with medulla of loosely interwoven hyphae, 
trichomatic hyphae, usually present, attached to the substratum by com- 
*Contributions from the Botanical Laboratory of Miami University—XIX 
