358 41. CALOPLACACEAE [166. Caloplaca 



verrucose, sometimes scattered and tending to disappear; apothecia small to 

 middle-sized, 0.3-1.3 mm. across, adnate to sessile, the disk flat to convex, rust- 

 colored to black, often subpruinose, the exciple evanescent; spores ellipsoid, 11-20 

 X 6-10 fi. 



On trees, old wood, and rocks, throughout the United States. 



12. Caloplaca festiva (Ach.) Zwackh., Flora 47:85. 1864. 



Lecidea caesiorufa var. festiva Ach., Syn. Lich. 44. 1814. Placodium festivum 

 (Ach.) Hepp. Blastenia festiva (Ach.) Mass. 



Thallus thin, gray to ashy, chinky to areolate, becoming more or less scattered 

 or disappearing; apothecia minute to small, 0.2-0.6 mm. across, sessile, the disk 

 flat to convex, bright orange to brownish red, the exciple thick, orange to brownish, 

 becoming flexuous or crenulate, often disappearing; spores oblong-ellipsoid, 11-17 

 X 5-7 fi. 



On rocks, Montana and California. 



13. Caloplaca Pollinii (Mass.) Jatta, Syll. Lich. Ital. 244. 1900. 



Blastenia Pollinii Mass., Flora 35:575. 1852. Placodium ferruginenm var. 

 Pollinii (Mass.) Hepp. Placodium ferruginenm var. nigricans (Nyl.) Tuck, 

 in litt. 

 Thallus thin, whitish, smooth to slightly wrinkled, tending to disappear; apothe- 

 cia small to middle-sized, 0.2-1.2 mm. across, adnate to sessile, the disk flat to 

 convex, olive-green to black, the exciple evanescent, when present entire, of the 

 same color as the disk; spores ellipsoid, 11-20 X 6-10 fx. 



On living and dead conifers, from New England and Maryland westward to 

 Nebraska and Minnesota. 



14. Caloplaca camptidia (Tuck.) Zahlbr., Cat. Lich. Univ. 7:83. 1930. 

 Lecanora camptidium Tuck., Proc. Am. Acad. 5:403. 1862. Placodium camp- 



tidium Tuck. 



Thallus thin, smooth to chinky and wrinkled or verrucose, ashy to brownish 

 gray; apothecia minute to small, 0.2-1 mm. across, sessile, the disk flat to convex, 

 reddish brown to dark chestnut-brown, white-pruinose, the exciple of the same color 

 as the thallus or slightly darker, entire; spores ellipsoid, 10-14 X 5-8 /a. 



On trees and wood, throughout eastern United States westward to Illinois, and 

 in Oregon and Texas. 



15. Caloplaca pyracea (Ach.) T. Fries, Sven. Vet. Akad. Handl. 7:25. 1867. 

 Parmelia cerina var. pyracea Ach., Meth. Lich. 176. 1803. Placodium pyraceum 



(Ach.) Anzi. Placodium cerinum var. pyraceum (Ach.) Branth & Rostr. 



Thallus very thin, dark ashy to whitish, scurfy-granulose, often disappearing; 

 apothecia minute to small, 0.2-0.6 mm. across, adnate to sessile, often numerous, 

 clustered, and angular, obscuring the thallus, the disk flat to convex, yellowish- to 

 dark-orange, the exciple thin, yellowish to whitish, usually disappearing early; 

 spores ellipsoid to ovoid-ellipsoid, 10-16 X 5-9 \i.. 



On rocks and old wood, northern United States and California. 



16. Caloplaca ulmorum Fink n. comb 



Placodium cerinum var. ulmorum Fink, Proc. Iowa Acad. Sci. 11:143. 1904. 

 Placodium ulmorum Fink. C. cerina var. ulmorum (Fink) Zahlbr. 



Thallus moderately thick, greenish gray to ashy, granulose-verrucose, irregularly 

 spread in small patches; apothecia small to middle-sized, 0.2-1.3 mm. across, 

 sessile, the disk concave to flat, dull waxy-yellow, roughened, somewhat pruinose, 

 the exciple ashy whitish, prominent, entire to subcrenulate or radiately striate; 

 spores ellipsoid, 8-18 X 5-10 /a. 



On elms, and rarely on oaks, cedars, and other trees, Ohio, Minnesota, Iowa, 

 and Kansas. 



