196 LECANORA. 



also here, and is marked by its densely powdery, yellowish thal- 

 lus, in which the fruit comes to appear immixed j such speci- 

 mens contrasting with the smooth, glaucescent thallus and ele- 

 vated, finally also larger fruit of the other. c is a small but 



marked form, not appearing to differ from the cited Italian one. 



t t t t Spores very large, simple. 



32. L. pallescens (L.) Schaer. j thallus from sub-cartilagineous 

 and chinky or plicate, at length sub-tartareous and tuberculose- 

 rugose ; dirty-white ; apothecia middling to ample, tumid ; the 

 more or less white-pruinose, and roughened disk from pale- or 

 now yellowish- white becoming flesh-coloured ; the erect margin 

 very entire, or now rugose-verrucose. Spores ellipsoid, ^ mic. 



Schcer. Enum. p. 78. Parmelia, Fr. L. E. p. 132. Tuck. 



Exs. n. 90. 



&. rosella, Tuck. ; the margin of the apothecia throwing out 

 several to many processes meeting at the centre, and dividing 

 the disk radiately into smaller ones. Gen. Lich. p. 125. 



Upon rocks (rarely with us), dead wood, trees, and mosses 

 probably throughout North America. Northern and middle 

 States, MuJileriberg Catal. 1818. Arctic America, Richardson. 

 Maryland and Virginia, Tuckerman. North Carolina, Curtis. 

 South Carolina, Eavenel. Florida, Chapman. Texas, Wright. 



California (rocks, well-marked), Bolander; and also trees. 



&, northern and middle States, Muhlenberg, etc. 1 incline to 



refer also here rather than to the next species a common bark- 

 lichen of the Pacific Coast (California, Bolander; Oregon, Hall; 

 British Columbia, Macoun; Alaska, Kellogg) which, with the 

 thinner, chinky crust of the present, offers entirely naked, and 

 at length reddish-brown apothecia. 



33. L. tartarea (L.) Ach. ; thallus thick, tartareous, granu- 

 late-conglomerate passing into nodulose, and isidioid conditions ; 

 grayish- white ; apothecia middling to ample, at length large; 

 the rugulose disk from yellowish-brown becoming brick-coloured, 

 naked ; the thick thalline margin very entire or wavy. Spores 

 ellipsoid, ^ mic. Parmelia, Fr. L. E. p. 133. 



Upon rocks, and on the earth, mosses, etc. Northern and 

 middle States, Halsey, 1823. Arctic America, at Cumberland 

 Gulf, Howgate exp. Ohio, Miss Biddlecome. Virginia and 

 North Carolina Mountains, Curtis. Mountains of South Caro- 



