—42— 



The apothecia are borne on the lobes of the thallus. They are usually 

 abundant, somewhat elevated or pedicellate. The disk is light chestnut, 

 growing darker with age, and perforated at the center. The margin, unlike 

 ciliaris, is entire. When young the apothecia have the characteristic shield 

 shape but as they develop they assume a round shape. Cctraria lacunosa 

 grows on trees and old fence rails and while not so generally found as C. cili- 

 aris is a very common species. 



Fig. I. C. ciliaris x I. 



Cetraria Ciliaris. Ach. (Plate V. 4, and 

 Fig. I.) This is the most generally distri- 

 buted of all the Cetrarias. It is found in 



^S^'^-<&^^®*S^^*'iX ■fiTnic?' North and South America, Europe and Asia, 

 yr^hnLtV^^ «tif^»'"i« s'-S* lr?l^ is especially abundant in Japan. It is 



usually fertile, and on the same tree maybe 

 found dozens of specimens in all stages of 

 growth. 



The thallus is foliaceous with crenate or 

 finely cut margins, which are fringed with 

 cilia, as the specific name, ciliaris, indicates. 

 These are very distinct and numerous on 

 the growing specimen, but disappear to some extent when pressed. When 

 young the thallus is greenish gray turning to olive and lastly to dark brown 

 with age. Beneath it is a greenish brown, with fibrils more or less numerous. 

 The lobes of the thallus are narrow and many cleft. 



The apothecia are marginal, rather large. The disk is a light chestnut 

 color which turns, as it develops, to a dark reddish brown. The margins are 

 crenulate, finely notched. This species is found on old rails and on trees, espe- 

 cially hemlocks and birches. It is very commcm throughout the Northern, 

 Middle, and Southern States. It is easily distinguished from Cetraria hicu- 

 ttosa. with which it grows, by the many cilia on the lobes of the thallus. 

 Sometimes the apothecia are .so numerous and crowded that it is difficult to 

 realize that they arc on the margin of the thallus. 



Cetraria iuniperina(L) Ach. (Plate V. i and 2.) Fig. 2 C. Islandica XI. 



This is a striking lichen on account of its bright yellow thallus, 



which rivals in coloring Ei'crnia vulpitia. The narrow crisped lobes 

 of the thallus give it a fluted appearance, it is sometimes pale yellow be- 

 low, then again the same bright yellow as the upper surface. 



The apothecia are submarginal, of medium size, and .somewhat elevated. 

 The disk is chestnut, the margin crenulate and often turned inward. 



Cetraria juniperi)ia, 7>ar. Pinastri Ach. is much like C. junipcrijia, 

 but has more comj^rcssed lobes with curled margins, which are thickly cov- 

 ered with bright yellow soredia. Both forms are found on trees throughout 

 the Eastern States. C. Pinastrii^ sometimes found on rocks farther North. 



