166. Caloplaca ] 41. CALOPLACACEAE 359 



17. Caloplaca gilva (Hoffm.) Zahlbr., in E. & P., Nat. Pfl. l x :228. 1907. 

 Verrucaria gilva Hoffm., Deutschl. Fl. 2:179. 1795. Placodium gilvwn (Hoffm.) 



Vainio. Placodium cerinum var. gilvum (Hoffm.) Tuck. 



Thallus thin, ashy gray to yellowish, granulose or warty, often scattered, becom- 

 ing inconspicuous or disappearing; apothecia minute to small, 0.2-0.6 mm. across, 

 becoming sessile, the disk slightly concave to convex, orange to brownish orange, 

 the proper exciple thin to moderately thick, yellow to light orange, surrounded by a 

 thin, finally disappearing thalloid one; spores oblong-ellipsoid, 12-16 X 5-7 /a. 



On trees, Massachusetts, Illinois, North Dakota, Washington, and California. 



18. Caloplaca Wrightii (Tuck.) Fink n. comb. 



Placodium jerrugineum var. Wrightii Tuck., Syn. N. A. Lich. 1:178. 1882. 

 Blastema ferruginea var. Wrightii (Tuck.) Hasse. C. ferruginea var. 

 Wrightii (Tuck.) Zahlbr. 

 Thallus moderately thick, light greenish gray to whitish, densely sprinkled over 

 with white granules or coralloid branchlets; apothecia small to middle-sized, 0.3-1 

 mm. across, adnate, the disk flat to convex, dark red to reddish brown, the exciple 

 moderately thick, lighter or colored like the disk, becoming flexuous, sometimes 

 bordered more or less by a thin thalloid one; spores ellipsoid, 12-19 X 6-9 /jl. 

 On trees, Texas and New Mexico. 



19. Caloplaca oxfordensis Fink; Hedrick, Mycologia 26:162. 1934. 



Thallus thin to moderately thick, composed of minute, flat to convex, dirty 

 gray and darkening granules, scattered or crowded into a continuous, areolate crust; 

 apothecia minute to small, 0.1-0.4 mm. across, adnate to subsessile, often crowded 

 and irregular, the disk slightly concave to flat or somewhat convex, orange to 

 brown or dusky, the thalloid exciple rather thin, orange to darker, becoming flexu- 

 ous; spores ellipsoid to oblong-ellipsoid, 13-16 X 5.5-8 fi. 



On exposed rocks, near Oxford, Ohio. 



20. Caloplaca jungermanniae (Vahl.) T. Fries, Nov. Act. Reg. Soc. Sci. Ups. 



III. 3:221. 1861. 

 Lichen jungermanniae Vahl., Nat. Selsk. Skr. II. 29. 1792. Placodium junger- 

 manniae (Vahl.) Tuck. Placodium fulvolutea (Arn.) Tuck. 

 Thallus thin, minutely granulose to subsquamulose, ashy or whitish; apothecia 

 small to middle-sized, 0.4-1.2 mm. across, sessile, the disk flat to slightly convex, 

 orange to brownish, the exciple thick, swollen, colored like the disk, becoming 

 flexuous and finally disappearing; spores oblong-ellipsoid, 14-23 X 7-11 p. 

 Over mosses, Colorado, Montana, Idaho, and Washington. 



21. Caloplaca variabilis (Pers.) Mull. Arg., Mem. Soc. Phys. Hist. Nat. Geneve. 



16:387. 1862. 

 Lichen variabilis Pers., Ann. Bot. Usteri 7:26. 1794. Placodium variabile (Pers.) 



Hepp. 

 Thallus roughened and chinky, grayish brown and blackening, areolate, the 

 margin sometimes squamulose; apothecia minute to small, 0.2-1 mm. across, ad- 

 nate, the disk flat, of the same color as the thallus, the exciple whitish to light 

 gray, entire to crenulate; spores oblong-ellipsoid, 13-20 X 5-9 /a. 

 On rocks, from the Rocky Mountains westward to California. 



22. Caloplaca amabilis Zahlbr., Bull. Torr. Club 35:298. 1908. 

 Placodium amabile (Zahlbr.) Fink. 



Thallus thick, greenish gray to rusty green, squamulose to subareolate, becoming 

 somewhat scattered; apothecia minute, 0.1-0.3 mm. across, adnate to sessile, some- 

 times angular when crowded, the disk flat to convex or wavy, yellow to tawny 

 yellow or orange, waxy, the exciple of the same color as the thallus, entire, soon 

 depressed; spores oblong-ellipsoid, 8-13 X 5-7 /a. 



On basaltic rocks, Arizona. 



