142. Lecanora] 38. LECANORACEAE 299 



12. Lecanora lacustris (With.) Nyl., Not. Sallsk. Faun. Flor. Fenn. 5:155. 1861. 

 Lichen lacustris With., Arr. Brit. PI. ed. 3.21. 1796. 



Thallus thin to rather thick, smooth, chinky to subareolate, pale brick-color 

 or yellowish green; apothecia minute to small, 0.2-0.6 mm. across, immersed, the 

 disk concave, reddish brown, the exciple rather thick, colored like the thallus, 

 becoming flexuous, often scarcely differentiated from the thallus; spores oblong- 

 ellipsoid, 11-17 X 5-6.5 ^t. 



On rocks, New England, New York, New Jersey, North Carolina, South Caro- 

 lina, Alabama, and Minnesota. 



13. Lecanora epulotica (Ach.) Leighton, Lich. Fl. Great Brit. 212. 1871. 

 Gyalecta epulotica Ach., Lich. Univ. 151. pi. 1, f. 7. 1810. L. subepulotica (Nyl.) 



Fink. 



Thallus thin, smooth to more or less rough, chinky to areolate, greenish gray 

 to yellowish or whitish gray; apothecia minute to small, 0.2-0.5 mm. across, im- 

 mersed, the disk slightly concave, pale flesh-colored to darker, the exciple thick, 

 colored' like the thallus, not always differentiated from the thallus; spores ellipsoid 

 to ovoid-ellipsoid, 11-17 X 6-9 ju.. 



On rocks, New England and Minnesota. 



14. Lecanora lavata (Magn.) Fink n. comb. 



Jonaspis lavata Magn., Meddel. Got. Bot. Tradgard 3:15. 1927. 



Thallus thin, smooth to somewhat irregular and minutely chinky, creamy yel- 

 low or tinged with rose; apothecia minute to small, 0.2-0.3 or rarely 0.6mm. 

 across, very numerous, immersed, often crowded and confluent, the disk slightly 

 concave, light reddish or yellowish brown, the exciple colored like the thallus; 

 spores 8, hyaline, oval, non-septate, 10 X 6 tt. 



On submerged rocks, Mt. Rainier, 8,000 feet, near Paradise Glacier, Washing- 

 ton. (Description compiled.) 



15. Lecanora atra (Huds.) Ach., Lich. Univ. 344. 1810. 



Lichen ater Huds., Fl. Angl. 445. 1762. Parmelia atra (Huds.) Ach. 



Thallus of moderate thickness, composed of granules usually run together into 

 a smoothish, warty, or areolate crust, greenish gray to ashy white; apothecia small 

 to middle-sized, 0.9-2 mm. across, more or less immersed to adnate, the disk flat 

 to somewhat convex, very black, the exciple rarely crenate and flexuous, occa- 

 sionally becoming black and rarely disappearing; hypothecium and hymenium 

 brown to brownish black; spores ellipsoid, 10-15 X 5-8 /*. 



On rocks and trees, throughout the United States. 



16. Lecanora glaucomela Tuck., Gen. Lich. 118. 1872. 



Thallus thin, smooth to somewhat rough, becoming wrinkled and somewhat 

 chinky, greenish gray; apothecia small to middle-sized, 0.6-1.2 mm. across, sub- 

 sessile, the disk flat to slightly convex, blackish brown to black, the exciple thin, 

 colored like the thallus, becoming crenulate and rarely disappearing; spores ellip- 

 soid, 17-23 X 9-12 /x. 



On trees, California and Oregon. 



:'. 



17. Lecanora melaena (Hedlund) Fink n. comb. 



L.polytropa var. melaena Hedlund, Bih. Svensk. Vet. Akad. Handl. 18. Ill 

 3:38. 1892. 



Thallus thin to rather thick, greenish gray to ashy, chinky to areolate, the 

 areoles sometimes obscurely crenate, sometimes scattered; apothecia small, 0.4-0.9 

 mm. across, immersed to partly superficial, the disk flat to strongly convex, olive- 

 blackish to dull black, the exciple of the same color as the thallus and commonly 

 disappearing; spores oblong-ellipsoid to ellipsoid, 8.5-11.5 X 5-6.5 /a. 



On rocks, northeastern Minnesota. 



