25. Anthracothecium ] 4. PYRENULACEAE 59 



A. Thallus very thin, inconspicuous or sometimes absent 



B. Spores more than 30 /x in length 3. A. pyrenuloides 



B. Spores less than 30 /j. in length 



C. Spores 5-7-septate transversely 2. A. staurosporum 



C. Spores 7-9-septate transversely 5. A. thelomorphum 



A. Thallus thin to thicker, plainly visible 

 B. Spores more than 35 n in length 



C. Thallus thin, smooth, greenish gray to ashy 4. A. libricola 



C. Thallus rather thick, smooth, whitish to olive-green, partly 



bordered by a blackish hypotha.lus 6. A. mucosum 



B. Spores less than 35 /jl in length 1. A. ochraceoflavum 



1. Anthracothecium ochraceoflavum (Nyl. ) Mull. Arg., Linnaea 63:44. 1880. 



Verrucaria ochraceofiava Nyl., Mem. Soc. Acad. Maine et Loire 4:50. 1858. 



Thallus thin, smooth to slightly rough, yellowish orange to yellow; perithecia 

 small to middle-sized, 0.3-0.7 mm. across, immersed in subhemispherical thalloid 

 warts, the superficial portion convex, black, the wall very thin, complete, the ostiole 

 minute, depressed, sometimes indicated by a whitish area; spores 8, brown, oblong- 

 ellipsoid to ellipsoid, 5-7-septate transversely and 1-3-septate longitudinally, 18-32 

 X 9-12 fx, arrangement obliquely uniseriate. 



On trees, Florida. 



2. Anthracothecium staurosporum (Tuck.) Zahlbr., Cat. Lich. Univ. 1:468. 



1922. 

 Pyrenula staurospora Tuck., in Willey, Enum. Lich. New Bedford, Mass. 38. 



1892. 

 Thallus thin, brownish yellow, smooth; perithecia minute to small. 0.1-0.4 mm. 

 across, largely immersed in convex thalloid warts, the wall very thin, complete, the 

 superficial portion convex with an inconspicuous ostiole, black; tinged brownish 

 within; spores 8, ellipsoid, tinged brown, 5-7-septate transversely and partly 1- 

 septate longitudinally, 16-24 X 7-9 /x, arrangement obliquely uniseriate. 

 On trees, Massachusetts. 



3. Anthracothecium pyrenuloides (Mont.) Mull. Arg., Linnaea 63:44. 1880. 



Try pet helium pyrenuloides Mont., Ann. Sci. Nat. Bot. II. 19:69. 1843. Pyrenula 

 pachycheila Tuck. A. pachycheilum (Tuck.) Zahlbr. 



Thallus rudimentary, the superficial portion very thin, smooth, sometimes 

 absent, and the imbedded portion indicated at the surface by an ashy or yellowish 

 gray coloration; perithecia middle-sized to large, 0.6-1 mm. across, immersed 1 or 

 more in thalloid warts, the superficial portion convex, black, the wall thin, com- 

 plete, the ostiole small, slightly depressed; spores 8, brown, oblong-ellipsoid to 

 ellipsoid, 5-9-septate transversely, and 1-2- or rarely 3-septate longitudinally, 30-65 

 X 12-23 ll, arrangement obliquely uniseriate to irregular. 



On trees, from Massachusetts to Florida and westward to Tennessee and Texas. 



4. Anthracothecium libricola (Fee) Mull. Arg., Linnaea 63:43, 44. 1880. 

 Pyrenula libricola Fee, Essai Crypt. Suppl. 82. 1837. 



Thallus thin, smooth, pale greenish gray to pale cream-colored or ashy; peri- 

 thecia minute to small, 0.1-0.6 mm. across, wholly or partly immersed, dimidiate, 

 superficial portion convex to hemispherical, black, the ostiole rarely visible, minute ; 

 spores light brown, oblong-ellipsoid, 7-9-septate transversely and 1-2-septate longi- 

 tudinally, 35-45 X 15—18 /x, obliquely uniseriately arranged. 



On trees, Florida. 



5. Anthracothecium thelomorphum (Tuck.) Zahlbr., Cat. Lich. Univ. 1:469. 



1922. 



Pyrenula thelomorpha Tuck., Gen. Lich. 275. 1872. 



Thallus inconspicuous, pale greenish gray, tinged with yellow, sometimes 

 scarcely visible; perithecia middle-sized or larger, 0.4-0.7 mm. across, solitary or 

 grouped in thalloid warts, largely immersed, the exposed portions subcorneal, black 



