THE LICHEN-FLORA OF CHTCAGO AND VICINITY. 27 



49. L. pallida, (Schreb.) Schaerer. Thallus thin, membranaceous, 

 smooth, cream-colored or darker; apothecia sessile, tumid; 

 whitish-buff, white-pruinose, the entire margin disappearing. 

 Spores ellipsoid. Parmelia, Schaer. Spicil. 396. Tuck. Syn., 

 185. 



On oaks and hickories near Joliet. This species and its 

 varieties are more abundant in some localities than in ours. 

 Varies greatly as to the apothecia. 



50. L< subfusca, (L. ) Ach. Thallus whitish or cinerascent, smooth, 

 rimulose, granulate, verrucose, soon diffract; apothecia plano- 

 convex, disk fuscous, becoming black, often pruinose, the thai- 

 line margin entire, flexuous or crenate. Spores ellipsoid. 

 Parmelia, Schaer. Spicil. 389, etc. 



Very common in our territory on oaks and other trees and also 

 on arenaceous rocks. There are several varieties. I have 

 specimens from Europe, Japan and the West Indies. Many 

 species, so called, have been made from this cosmopolite. 



51. L. subfusca, (L.) Ach., var. allophana, Ach. Thallus granu- 

 late, verrucose; apothecia fuscous-black, margin flexuous and 

 crenate. Lich. Uni. Nyl. 395, 



On oaks in various localities; not uncommon. 



52. L, subfusca, (L.) Ach., var. argentata, Ach. Apothecia smaller, 

 margin entire. Spores smaller. Lich. Univ. Nyl. Syn, 393. 

 Occasionally found on shrubs and trees in our territory. 



53. L subfusca, (L) Ach., var. distans, Ach. 



Common on the same substrates as the preceding forms; 

 apothecia flat and pale, margin crenulate. Spores smaller 

 than in number 52. L. distans, Ach. L. U. 39*7. 



54. L, hageni, Ach. Thallus cinerascent, verruculose or want- 

 ing; apothecia small or minute, crowded, plane or tumid; pale 

 to fusco-rufous or sometimes pruinose; margin white, com- 

 monly crenate or entire; may be excluded. Th. Fr. Scand. 

 250. L. umbrina, (Massalongo) Nyl. 



On rails near Lemont and on calcareous rocks. Some condi- 

 tions are known as L. umbrina, (Mass.) Nyl. The observer 

 cannot but see close relations in L. hageni to L. subfusca 

 and the next following species. 



