166. Caloplaca ] 41. CALOPLACACEAE 357 



to slightly convex, yellowish orange to chestnut-brown, the exciple moderately 

 thick, colored like the thallus, becoming flexuous; spores oblong-ellipsoid, 12-16 X 

 5.5-7.5 /x. 



On rocks, Alabama and Tennessee. 



7. Caloplaca citrina (Hoffm.) T. Fries, Nov. Act. Reg. Soc. Sci. Ups. III. 3:218, 



219. 1861. 

 Verrucaria citrina Hoffm., Deutschl. Fl. 2:198. 1795. Placodium citrinum 



(Hoffm.) Hepp. 

 Thallus of minute granules, scattered or compacted into an irregular or wide- 

 spread subareolate crust, lemon-yellow; apothecia minute to small, 0.2-0.5 mm. 

 across, adnate, the disk flat, waxy-yellow to orange, the exciple pale yellow to 

 orange, subgranulose and disappearing ; spores ellipsoid to oblong-ellipsoid, 8-14 X 

 4.5-7 fi. 



On rocks and mortar, throughout northern United States, and in South Carolina. 



8. Caloplaca discolor (Willey) Fink n. comb. 



Placodium jerrugineum var. discolor Willey, in Tuck., Syn. N. A. Lich. 1:178. 

 1882. C. ferruginea var. discolor (Willey) Zahlbr. 



Thallus thin, pale to bright yellow, granulose, more or less scattered; apothecia 

 minute to small, 0.2-1 mm. across, adnate to sessile, the disk flat to convex, 

 rusty red to reddish brown, the exciple evanescent, when present of the same color 

 as the disk; spores ellipsoid, 11-18 X 7-1 1 //.. 



On trees, New England and New York. 



9. Caloplaca cerina (Ehrh.) T. Fries, Nov. Act. Reg. Soc. Sci. Ups. III. 3:218. 



1861. 



Lichen cerinus Ehrh., in Hoffm., PI. Lich. 2:62. pi. 21, f. B. 1789. Placodium 

 cerinum (Ehrh.) Naeg. 



Thallus thin, ashy to lead-gray, brownish or whitish, smooth and chinky to 

 subareolate, often verrucose, becoming irregular and widespread, rarely disappear- 

 ing; apothecia small to middle-sized, 0.2-1.3 mm. across, adnate to sessile, the 

 disk slightly concave to convex, lemon-yellow to reddish or greenish brown, the 

 exciple of the same color, whitish, or of the same color as the thallus, sometimes 

 raised, entire or becoming wavy; spores ellipsoid, 8-18 X 5-10 /a. (Plate 43 a.) 



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



var. areolata Zahlbr., Oesterr. Bot. Zeitschrift 53:289. 1903. 

 Thallus thin, more or less widespread, lead-gray, distinctly areolate, the areoles 

 usually flat; apothecia 1-4 in each areole, round to angular and crowded. 

 On rocks, Vermont. 



10. Caloplaca sideritis (Tuck.) Zahlbr., Trav. Sous. Troit. Soc. Imp. Russe 



12:92. 1911. 

 Lecanora sideritis Tuck., Am. Journ. Sci. II. 25:426. 1858. Placodium ceri- 

 num var. sideritis Tuck. Placodium sideritis (Tuck.) Fink. C. cerina var. 

 sideritis (Tuck.) Merrill. 

 Thallus moderately thick, iron to greenish gray, continuous, of somewhat scaly 

 and often convex warts or areoles; apothecia small to middle-sized, 0.2-1 mm. 

 across, immersed to adnate, the disk flat to convex, yellowish rust-colored to rusty- 

 brown or black, the exciple of the same color as the thallus, entire, sometimes dis- 

 appearing; spores ellipsoid, 8-15X5-8 /a. 

 On rocks, northeastern United States. 



11. Caloplaca ferruginea (Huds.) T. Fries, Nov. Act. Reg. Soc. Sci. Ups. III. 



3:223. 1861. 



Lichen jerrugineum Huds., Fl. Angl. ed. 2. 526. 1778. Placodium jerrugineum 

 (Huds.) Rabh. Placodium jerrugineum var. Boianderi Tuck. Blastenia fer- 

 ruginea (Huds.) Mass. 



Thallus commonly thin, ashy to whitish, smooth and chinky to wrinkled and 



