— 6o — 



pothecia are medium, have a yellow or orange disk with cilia on the margin. 

 Found fertile in the Southern States, and sterile in the North, where it is not 

 common. 



Theloschistes parietinus (L.) 

 Norm. (Fig. 3.) Thallus foli- 

 aceous, usually orbicular; the 

 lobes, which are short, thin, 

 rounded, crenate and somewhat 

 rugose, turn upward at their mar- 

 gins, otherwise cling closely to 

 the substratum by means of short 

 rhizoids. The apothecia are 

 smaller than in T. chrysophthal- 

 mus and are sessile; the disk is 



Fig. 3. Theloschistes parietinus X2. orange, with a thin, wavy mar- 

 gin; they are chiefly toward the centre and are crowded. This is one of the 

 commoner species and resembles Parmelia in habit of growth. Is found on 

 trunks and branches of trees, stone walls and rocks, is especially fine near 

 lakes of any size. 



Theloschistes polycarpus (Ehrh.) 

 Tuckm. (Fig. 4.) Thallus foliaceous, re- 

 duced, with narrow, many cleft divisions, 

 which are short and rounded. In color 

 greenish-yellow, turning darker with age. 

 The underside much wrinkled and covered 

 with short white rhizoids. The apothecia 

 are medium, the disk is concave, bright 

 orange with crenulate margin. They are 



Fig. 4. Theloschistes often so numerous as to almost cover the 



polycarpus. j^^^g ^y^^ thallus, except at the outer 



edge. This species usually occurs in small, orbicular patches, but occa- 

 sionally larger specimens are found ; it grows on trees, dead wood and on 

 rocks. 



Theloschistes lychneus (Nyl. ) 

 Tuckm. (Fig. 5 ) This species is 

 sometimes confused with Cetraria 

 juniperina var. pinastri which 

 it resembles, but from which it 

 can be distinguished readily, as 

 the thallus of the Cetraria is 

 larger, more leaf-like, the under- 

 side is always yellow, the soredia 



Fig. 5. Theloschistes lychneus. are sulphur color, while in /j/^:^- 



neus the thallus is flatter, more appressed, light gray underneath and covered 

 with fine rhizoids ; the soredia are light lemon color. The lobes of the thal- 

 lus of T. lychneus are broader than in T. polycarpus, and are not quite 



