106. Heppia] 29. HEPPIACEAE 169 



smooth to wrinkled, and flesh-colored to brown below; apothecia small, 0.3-0.5 mm. 

 across, deeply immersed to adnate, the disk flat, dark brown, the exciple very thin, 

 colored like the thallus; spores spheroidal to oblong, 3-5 X 1-2 jx. 



On rocks, Massachusetts, Maryland, Arkansas, Minnesota, and California. 



2. Heppia Bolanderi (Tuck.) Vainio, Act. Soc. Faun. Flor. Fenn. 7:215. 1890. 

 Pannaria Bolanderi Tuck., Gen. Lich. 51. 1872. Endocarpiscum Bolanderi Tuck. 

 Thallus thin, composed of minute, crowded, subimbricate, smooth, olive-green 



to dark brown squamules, with raised, crenate to lobate, sometimes obscurely pow- 

 dery margins; apothecia minute to small, 0.3-0.6 mm. across, immersed to adnate, 

 the disk flat to convex, reddish brown, the exciple thin, colored like the thallus; 

 spores ellipsoid, 4-6 X 1.5-2 fi. 



On rocks, Arizona and California. 



3. Heppia polyspora Tuck., Syn. N. A. Lich. 1:115. 1882. 

 Endocarpiscum polyspora (Tuck.) Fink. 



Thallus squamulose-foliose, thin, very small to small, olive-green to brownish, 

 closely attached, round to irregular, flat or depressed, with raised margins; apo- 

 thecia minute to small, 0.2-0.5 mm. across, immersed, the disk concave to flat, dull 

 brown; hypothecium hyaline to yellowish; spores minute, subspherical to ovoid, 

 4-7.5 X 2-5 fx. 



On soil and rocks, Minnesota, Nebraska, Arizona, Colorado, and California. 



4. Heppia deserticola Zahlbr., Bull. Torr. Club 35:300. 1908. 



Thallus thin, composed of more or less clustered, rather small, flat squamules 

 with raised, incised to lobate margins, light to darker brown; apothecia small to 

 middle-sized, 0.4-0.8 mm. across, immersed, 1 in each squamule, the disk slightly 

 concave to flat, brownish black, the exciple very thin, colored like the thallus, soon 

 disappearing; spores ovoid to oblong-ovoid, 7—10 X 3-5 /x. 



On basaltic boulders, near Tucson, Arizona, 

 var. minor Zahlbr., Ann. Mycol. 7:474. 1909. 



Thallus composed of minute to small, more oi* less clustered or scattered, flat 

 or depressed toward the center, brownish to dark brown squamules; apothecia 

 immersed to adnate. 



On rocks, Arizona. 



5. Heppia terrena Nyl.; Hasse, Bull. Torr. Club 24:445. 1897. 



Thallus thin, composed of small, closely attached, usually scattered, flat, round 

 to slightly irregular, dark olive-green squamules, with the margins usually slightly 

 raised; apothecia small to middle-sized, 0.4-0.75 mm. across, partly immersed to 

 adnate, solitary and often occupying nearly the whole squamule, the disk flat, red- 

 dish brown to brown, the exciple very thin, colored like the thallus, or turning 

 brownish; spores globose, 3.5—4.5 ju across. 



On soil, southern California. 



6. Heppia leptopholis Nyl., in Hasse, Lich. South. Calif. 10. 1898. 



Thallus composed of moderately thick, medium-sized, closely attached, con- 

 cave to flat-often finely reticulated and fissured, yellowish to olive-green squamules; 

 apothecia small, 0.35-0.5 mm. across, immersed, 1-4 or 5 in each squamule, the 

 disk punctiform to concave or flat, reddish brown, the exciple rudimentary or 

 absent; spores 16-24, globose, 4.5-6^, across. 



On soil, southern California. 



7. Heppia Hassei Zahlbr., Beih. Bot. Centralb. 13:157. 1902. 



Thallus thin, composed of small, appressed, round to somewhat irregular and 

 lobulate-crenate, olive-green to brownish squamules, with slightly raised margins; 

 apothecia minute, 0.1-0.4 mm. across, immersed 1 in each squamule, the disk 

 flat, punctiform to plainly open and reddish brown, the exciple absent or very 

 thin, colored like the thallus; spores ovoid-ellipsoid to subglobose, 5-7 X 3.5-4 u. 



On rocks, southern California. 



