IOWA ACADEMY OF SCIENCES. 
141 
Parmelia borreri Turn, in Trans. Linn. Soc. 148. 1808. 
On trees, frequent. (Young for m.) 
Parmelia borreri Turn. var. rudecta (Ach.) Tuck. Syn. 
Lich. New Eng. 26. 1848. 
On sandstone, common. 
Parmelia caperata (L.) Ach Meth. Lich. 216. 1803. 
On rocks, infrequent. 
Physcia hypoleuca (Ach.) Tuck. Syn. Lich. New Eng. 33. 
" 1848. 
On trees, frequent. 
Physcia speciosa (Wulf.) Nyl. in Act. Soc. Linn. Bord. 
“ (Ser. 3) 1:307. 1856. 
On rocks, rare. (Cortex of hyphae.) 
Physcia pulverulenta (Schreb.) Nyl. Act. Soc. Linn. 
Bord. (Ser. 3) 1:308. 1856. 
On sandstone, frequent. 
Physcia stellaris (L.) Tuck. Obs. North Amer. Lich. 395. 
1860. 
On trees, common. 
Physcia asteroidea (Fr.) Nyl. Act. Soc. Linn. Bord. (Ser. 3) 
1:308. 1856. 
On trees, infrequent. 
Physcia caesia (Hoffm.) Nyl. Act. Soc. Linn. Bord. (Ser. 3) 
1:308. 1856. 
On trees. (Species generally supposed to occur only 
on rocks. Iowa species have formerly been referred 
to Physcia gr anulif era, but upper cortex is cellular.) 
Physcia obscura (Ehrh.) Nyl. Act. Soc. Linn. Bord. (Ser. 3) 
1:309. 1856. 
On granite, rare, but common on trees. 
Physcia adglutinata (Elk.) Nyl. Syn. Lich. 428. 1860. 
On trees, rare. 
Peltigera rufescens (Neck.) Hoffm. Deutschl. FI. 2:107. 
1795. 
On shaded earth, rare. 
Peltigera canina (L.) Hoffm. Deutchl. FI. 2:106. 1797. 
On earth, rare. 
