298 38. LECANORACEAE [ 142. Lecanora 



6. Lecanora mutabilis (Ach.) Nyl., Mem. Soc. Sci. Nat. Cherb. 2:324. 1854. 

 Urceolaria mutabilis Ach., Lich. Univ. 335. 1810. L. verrucosa f. mutabilis 



(Ach.) Blombg. et Forss. 



Thallus moderately thick, warty, chinky to subareolate, dark ashy gray, varying 

 toward yellowish; apothecia small to middle-sized, 0.5-1 mm. across, immersed, 

 varying toward superficial, the disk deeply to slightly concave, commonly black, 

 opening tardily, the exciple thick and inflexed, colored like the thallus; spores 

 ellipsoid. 30-52 X 16-34 /x. 



On trees, Massachusetts, New York, and Minnesota. 



7. Lecanora laevata (Ach.) Nyl., Not. Sallsk. Faun. Flor. Fenn. 8:137. 1866. 

 Sagedia laevata Ach., Vet. Akad. Nya Handl. 164. 1809. L. cinerea var. laevata 



(Ach.) Tuck. 



Thallus thin, smooth to slightly rough, chinky to subareolate, greenish to dirty 

 gray, sometimes showing a black hypothallus; apothecia minute to small, 0.2-0.6 

 mm. across, immersed, the disk concave, black, the exciple thin, colored like the 

 thallus, becoming swollen, sometimes scarcely differentiated from the thallus; spores 

 ellipsoid, 15-26 X 9-16 fi. 



On rocks, Maine, Massachusetts, Alabama, Minnesota, Missouri, California, 

 and Washington. 



8. Lecanora cinerea (L.) Rohling, Deutschl. Fl. 3:90. 1813. 



Lichen cinereus L., Mant. PI. 1:132. 1767. Parmelia cinerea (L.) Hepp. 



Thallus thin to moderately thick, rough, chinky-areolate, ashy white to greenish 

 and rarely blackening, on a black hypothallus; apothecia small to middle-sized. 

 0.5-1 mm. across, immersed, the disk concave to flat, black, the exciple thin, colored 

 like the thallus or sometimes blackening, rarely disappearing; spores ellipsoid or 

 rarely subglobose, 13-27 X 8-16 ft. 



On rocks, throughout the United States, 

 var. microspora Fink, Cont. U.S. Nat. Herb. 14 l :184. 1910. 



Thallus thin, rough, blackish olive; apothecia small, 0.4-0.6 mm. across; spores 

 oblong-ellipsoid, 11-16 X 6-10//.. 



On rocks, Minnesota. 



9. Lecanora deplanans Nyl, Bot. Gaz. 22:334. 1896. 



Thallus thin, smooth, chinky to areolate, greenish gray to ashy; apothecia 

 minute to small, 0.25-0.6 mm. across, immersed, the disk slightly concave to flat, 

 reddish brown, the exciple thin, colored like the thallus, and finally somewhat 

 raised; spores short-ellipsoid, 13-16 X 8-10 ti. 



On rocks, West Virginia. 



10. Lecanora cinereorufescens (Ach.) Nyl., Not. Sallsk. Faun. Flor. Fenn. 



5:154, 155. 1861. 



Urceolaria cinereorufescens Ach., Lich. Univ. 677. 1810. 



Thallus thin, smooth to warty and chinky to areolate, the areoles sometimes 

 scattered, pale to darker grayish on a black hypothallus ; apothecia small to middle- 

 sized, 0.4-0.8 mm. across, immersed to adnate, the disk concave to flat, reddish to 

 reddish brown, the exciple colored like the thallus; spores ellipsoid, 12-20 X 

 7-10 fi. 



On rocks, Utah and Oregon. Our spore measurements are much larger than 

 Tuckerman's and agree well with European material examined. 



11. Lecanora odora (-Ach.) Tuck., Syn. N. A. Lich. 1:199,200. 1882. 

 Gyalecta odora Ach., in Schaer., Lich. Helv. Spic. 80. 1826. 



Thallus thin, becoming somewhat rough, chinky-areolate, sometimes crumbling, 

 grayish to ashy; apothecia minute to small, 0.2-0.5 mm. across, immersed, the 

 disk concave, yellowish flesh-colored, the exciple thin, colored like the thallus or 

 paler, becoming flexuous; spores ovoid-ellipsoid, 10-13 X 4-6 fi. 



On rocks, New Hampshire. 



