228 HERRE 



proper margin thin, more or less undulate, usually persistent; 

 thalline margin obsolete; spores ellipsoid to broadly-ellipsoid, 

 6.25 10 



- A*. 

 12.25 22 



This well-nigh cosmopolitan lichen occurs with us on the bark of 

 oaks in the mountains and on rocks, especially along the seashore. 



A variable plant with a number of rock-dwelling forms. 



One of these, Blastema ferruginea bolanderi (Tuck.), is distin- 

 guished by its having no thallus and the apothecia being usually 

 of a bright vermilion. It is abundant on maritime rocks. 



LVIII. CaloplacaTh. Fr. 



Caloplaca Th. Fries, Gen. Heterol. Europ. 70. 1861. 



Thallus crustaceous to fruticose, usually yellow, becoming pur- 

 plish red with KOH. 



Apothecia lecanorine, with a thalline margin; hypothecium clear, 

 upon an algal layer; asci with 8 spores. 



Species numerous, often quite variable and very difficult to define; 

 scattered over the whole earth and growing upon a great variety of 

 substrata. 



KEY TO THE SPECIES. 



A. Thallus fruticose, of terete, nodulose branches. . . i. coralloides 

 A A. Thallus crustaceous to sub-foliaceous. 



B. Apothecia dark brown to black 4. variabilis 



BB. Apothecia some shade of orange or yellow. 

 C. Thallus marginally lobed or sub-foliaceous. 



D. Lobes linear to cylindrical, much branched. . . .2. elegans 

 DD. Lobes marginally plicate or imbricate, broad .3. murorum 

 CC. Thallus not lobate or sub-foliaceous. 

 E. Thallus gray, ashy or dusky. 



F. Hypo thallus concolorous; thallus faint reddish 



with KOH -5. cerina 



FF. Hypothallus blue black; thallus crimson with 



KOH 6. gilva 



EE. Thallus yellow, orange or red. 



G. Thallus granulose, lemon-yeUow to greenish 



or grayish 7. citrinum 



GG. Thallus not granulose. 



H. Thallus of turgid, crenate squamules, pale 



or tawny yellow 8. bolacinum 



HE. Thallus of minute areoles, fissured; orange- 

 red 9. cinnabarina 



