376 HERRE 



ff. Thallus usually forming only a border to the large, crowded, 



imbedded apothecia 5. litnosuin^ 377- 



ee. On limestone rocks. 



g. Thallus thick, undulate, plicate 6. plicatile^ 37S 



dd. Thallus minute, squamulose or crustose...7. cristatellum, 37S. 



I. COLLEMA AGGREGATUM Nyl. 

 Thallus small or medium size, circular, irregularly lobed, 

 with crenate margin ; marked by thick, rough, anastomosing 

 ridges densely covered by black granules ; more or less fenes- 

 trate ; color dark green or black ; beneath pale, smooth, much 

 wrinkled and pitted ; apothecia numerous, mostly on the ridges ; 

 disk from concave becoming flat or even convex ; reddish or 

 darkening ; margin entire ; spores fusiform, long, plurilocular, 

 *±'»mic. 



4-5 



On trees. Not rare in the foothills. 



Collana agg-regatum Nyl. Mem. Soc. Sc. Nat. Cherb. 2 : 

 318. 1854. 



2. COLLEMA VESPERTILIO (Lightf.) Wainio. 

 Thallus of medium size, orbicular, thin, closely appressed ; 

 lobes rounded, with entire or crenate margin; surface naked, 

 smooth, radiately wrinkled and thickly pustulate; color 3'ellovv- 

 green, very dark green, and black ; beneath paler or concolor- 

 ous, lacunose or pitted ; apothecia small, usually very numer- 

 ous and crowded ; disk reddish or blackening ; plane, becom- 

 ing convex ; spores needle-shaped or fusiform, long, plurilocular, 

 ^i!^;li mic. 



On trees and perhaps occasional on rocks. Common in the 

 foothills at moderate elevations. Our most abundant Collana. 

 Lichen vesperti'lio Lightfoot, Flora Scotica 2 : S40. 1777. 

 Collcma vcspcriilio Wainio, Act. Soc. Faun. Fl. Fenn. 7 : 235. 



1890. 



3. COLLEMA NIGRESCENS (Huds.) Wainio. 



Thallus medium size, more or less orbiculate, thin, marginally 

 closely appressed, the rounded lobes with margins more or less 

 undulate or crenate ; surface radiately ridged and pustulate, 

 finally densely isidiose pulverulent; color ver}' dark green or 



