142. Lecanora ] 38. LECANORACEAE • 293 



globose, greenish gray to ashy, confluent wartlike elevations; apothecia small to 

 middle-sized, 0.3-0.6 mm. across, 1-several immersed in each wartlike elevation, 

 solitary and protuberant or at length clustered or united into crowded, irregular 

 groups, the ostioles black; hypothecium hyaline to cloudy; spores 2- rarely 4, 6, 

 or 8, yellowish, oblong-ellipsoid to ellipsoid-pointed, 95-195 X 25-68 p.. 

 On soil and over mosses, New Hampshire, New York, and Minnesota. 



18. Pertusaria globularis (Ach.) Tuck., Proc. Am. Acad. 1:277. 1848. 



Porina globularis Ach., Syn. Meth. Lich. 112. 1814. 



Thallus thin, minutely granulose to densely covered with short or sometimes 

 longer and branched coralloid branchlets, greenish gray to ashy; apothecia small, 

 0.25-0.5 mm. across, subsessile, sometimes united in groups of 2-several, the 

 ostioles sunken and flesh-colored to blackish; hypothecium hyaline to pale brown- 

 ish; spores 2-4, oblong-ellipsoid, 65-110 X 34-52 p.. 



Over mosses, from New England to Alabama, and westward to Arkansas. 



OTHER SPECIES REPORTED 



Pertusaria amara (Ach.) Nyl. — Maine and Washington. 



Pertusaria globulifera (Turn.) Mass. — California. 



Pertusaria rhexostoma Nyl. — North America. 



Pertusaria scutellaris Hue — Maine. 



Pertusaria texana Mull. Arg. — Texas. 



Pertusaria xanthodes Mull. Arg. — Texas. 



38. LECANORACEAE 



Thallus crustose, scaly, squamulose, or rarely even fruticose, differentiated into 

 cortical, algal, and medullary layers, rarely plectenchymatous throughout, attached 

 to the substratum by hyphal rhizoids; apothecia round, immersed to adnate or 

 sessile, with a well-developed thalloid exciple and rarely a poorly developed proper 

 one. 



The algal hosts are Pleurococcus and Protococcus. 



A. Spores non-septate 



B. Spores large 143. Ochrolechia 



B. Spores small 



C. Thallus yellow to orange 151. Candelariella 



C. Thallus rarely yellow or orange 142. Lecanora 



A. Spores septate 



B. Spores transversely 1-many-septate 

 C. Spores 1-3 -septate 



D. Spores constantly 1 -septate or rarely becoming 3-septate 



E. Thallus yellow to orange 151. Candelariella 



E. Thallus not yellow or orange 



F. Thallus crustose 145. Lecania 



F. Thallus squamulose 146. Solenopsora 



D. Spores 1-3-septate 144. Icmadophila 



C. Spores 3-many-septate 



D. Apothecia more or less immersed 



E. Paraphyses unbranched 149. Phlyctella 



E. Paraphyses branched and interwoven 150. Phlyctidia 



D. Apothecia adnate to sessile 147. Haematomma 



B. Spores transversely and longitudinally septate 148. Phlyctis 



142. Lecanora Ach., Lich. Univ. 77. pi. 7, f. 3-7. 1810. 



Thallus crustose to rarely subfoliose or foliose, the crustose forms showing no 

 differentiation or poorly developed indistinct upper cortex, algal and medullary 

 layers, and attached to the substratum by hyphal rhizoids, the foliose forms dif- 

 ferentiated into a well-developed, gelatinized pseudocellular upper cortex, well- 

 developed algal and medullary layers, and a thin, poorly developed lower cortex; 



