142. Lecanora ] 38. LECANORACEAE 297 



J. Disk not pruinose 25. L. atrynea 



I. Spores 8-13 X 3.5-5.5 fi 33. L. dispersa 



H. Disk dark red 31. L.Willeyi 



D. Spores rarely less than 16 fi in length 

 E. Spores ellipsoid or ovoid-ellipsoid 

 F. On trees 



G. Thallus lemon-yellow within 21. L. granulifera 



G. Thallus whitish within 16. L. glaucomela 



F. On rocks 45. L. Bockii 



E. Spores spherical 30. L. praecrenata 



1. Lecanora calcarea (L.) Nyl., Not. Sallsk. Faun. Flor. Fenn. 5:154. 1861. 

 Lichen calcareus L., Sp. PI. 1140. 1753. Parmelia calcarea (L.) Hepp. 

 Thallus rough, chinky to areolate or warty, greenish gray to rarely whitish, 



often disappearing; apothecia small to middle-sized, 0.5-1 mm. across, immersed 

 to rarely adnate, the disk flat, light brown to blackish, and commonly more or 

 less grayish pruinose, the exciple thin, colored like the thallus, becoming wrinkled; 

 spores 2-8, subglobose to ellipsoid, 15-27 X 9-22 /x. 



On rocks, throughout northern United States, and extending southward through 

 California. 



2. Lecanora iowensis Fink; Hedrick, Mycologia 26:161. 1934. 



Thallus thin, greenish gray to ashy, finely whitish pulverulent, chinky to areo- 

 late, the areoles small and flat, rarely lobed toward the margins; apothecia minute 

 to small, 0.25-0.7 mm. across, immersed to adnate, 1-2 in each areole, the disk 

 slightly concave to flat, light to darker brown or blackish, beneath a persistent 

 grayish white-pruinose cover, the exciple entire, becoming somewhat flexuous, 

 colored like the thallus or darkening; spores oblong-ellipsoid, 10-14 X 5-8 /a. 



On calcareous rocks, near Fayette, Iowa. 



3. Lecanora contorta (Hoffm.) Stiz. ; Reching., Verh. Gesell. Vien. 65:199. 1915. 



Verrucaria contorta Hoffm., Descr. PI. Crypt. 1:97. pi. 22, f. 1-4. 1790. L. 

 calcarea var. contorta (Hoffm.) Hepp. L. calcarea var. monstrosa Lamy. 



Thallus thick, composed of irregular, centrally elevated and marginally de- 

 pressed, greenish lead-colored or grayish white, sometimes scattered areoles; 

 apothecia minute to small, 0.3-0.8 mm. across, immersed to scarcely adnate, the 

 disk flat and sometimes punctiform, commonly grayish pruinose, the exciple thick, 

 colored like the thallus; spores 2-4, subglobose, 16-30 X 12-20 /x. 



On rocks, throughout the United States, but not common. 



4. Lecanora gibbosa (Ach.) Nyl., Mem. Soc. Imp. Sci. Nat. Cherb. 5:113. 1857. 

 Lichen gibbosus Ach., Lich. Suec. 30. 1798. L. cinerea var. gibbosa (Ach.) Nyl. 

 Thallus thick, rough, often crumbling, warty-areolate, greenish to brownish 



gray, on a blackening hypothallus; apothecia small to middle-sized, 0.6-1.5 mm. 

 across, immersed to adnate, the disk concave to flat, black, the exciple thin, colored 

 like the thallus, becoming slightly crenulate, often blackening; spores subspherical 

 to ellipsoid, 16-30 X 10-18 /*. 



On rocks, from New Hampshire to Alabama, westward to Iowa and Minnesota, 

 and recurring in California. 



5. Lecanora verrucosa Ach., Lich. Univ. 354. 1810. 



Urceolaria verrucosa Ach., Lich. Univ. 339. 1810. Parmelia verrucosa (Ach.) 

 Sprengl. 



Thallus rather thick, composed of minute to small, greenish gray to whitish or 

 ashy warts; apothecia small to middle-sized, 0.6-1.2 mm. across, immersed to 

 adnate and subsessile, the disk concave to flat, black and sometimes grayish 

 pruinose, often nearly closed, the exciple thin to rather thick, colored like the 

 thallus, often inflexed, becoming flexuous; spores ellipsoid, 30-45 X 16-30 /x. 



On soil and mosses, New Hampshire, North Carolina, Rocky Mountains, Cali- 

 fornia, and Washington. 



