230 33. LECIDEACEAE [ 126. Bacidia 



16. Bacidia luteola (Schrad.) Mudd, Man. Brit. Lich. 183. 1861. 



Lichen luteolns Schrad., Spic. Fl. Germ. 85. 1794. Biatora luteola (Schrad.) 

 E. Fries. Biatora rubella (Hoffm.) Rabh. B. rubella (Hoffm.) Mass. Biatora 

 rubella var. porriginosa (Ach.) Tuck. 



Thallus of minute, scattered or continuous and subscurfy or chinky, greenish 

 gray to yellowish or whitish granules, sometimes disappearing; apothecia small to 

 middle-sized, 0.5-1.35 mm. across, adnate to sessile, the disk flat to convex, reddish 

 yellow to reddish brown or obscurely white-pruinose, the exciple paler, thick, 

 finally disappearing; hypothecium hyaline to yellowish brown; spores 5-11- and 

 rarely 15-septate, 45-65 X 3-4 fx. 



On trees, New England, and westward to Missouri, Minnesota, and Oregon. 



17. Bacidia fuscorubella (Hoffm.) Bausch, Verh. Ver. Carls. 4:107. 1869. 

 Verrucaria fuscorubella Hoffm., Deutschl. Fl. 2:175. 1795. 



Thallus granulose, becoming wrinkled and chinky, greenish gray to ashy, hypo- 

 thallus finally blackening; apothecia small to middle-sized, 0.6-1.5 mm. across, 

 subsessile, the disk flat to slightly convex, pale brown or reddish to darker and 

 black, the exciple of the same color or white-pruinose, often transversely striate, 

 finally disappearing; hypothecium yellow to brown; spores about 6-13-septate, 

 40-75 X 3-4 /x. 



On trees and rarely on rocks, throughout the United States. 



18. Bacidia Clementis Hasse, Bryologist 13:61. 1910. 



Thallus thin to moderately thick, ashy to whitish, coarsely granulose, becoming 

 chinky; apothecia small to middle-sized, 0.2-0.8 mm. across, sessile, the disk flat 

 to convex, brownish black to black, the exciple thin, black, soon disappearing; 

 hypothecium yellowish to brownish; spores 8, hyaline, cylindrical with round ends, 

 curved, 14-17-septate, 60-80 X 4-5 fi. 



On trees, southern California. 



19. Bacidia arceutina (Ach.) Rehm; Arm, Verh. Gesell. Wien. 29:624. 1869. 

 Lecidea luteola var. arceutina Ach., Meth. Lich. 61. 1803. Biatora luteola var. 



arceutina (Ach.) Tuck. Biatora effusa var. arceutina (Ach.) Tuck. 



Thallus very thin, smooth to granulose or scurfy, sometimes chinky, ashy to 

 whitish; apothecia minute to small, 0.2-0.6 mm. across, sessile, the disk flat to 

 strongly convex, light brown to blackish, the exciple darker, finally disappearing; 

 hypothecium yellowish; spores indistinctly many-septate, flexuous, 35-50 X 1.2-2 //,. 



On trees, Massachusetts and Oregon. 



20. Bacidia muscorum (Swartz) Mudd, Man. Brit. Lich. 184, 1S5. 1861. 

 Lichen muscorum Swartz, Meth. Muse. 36. 1781. Biatora muscorum (Swartz) 



E. Fries. B. atrosanguinea (Hepp) Anzi. 



Thallus of minute granules, usually compacted and wrinkled-verrucose, greenish 

 gray to whitish; apothecia small to middle-sized, 0.4-1.2 mm. across, adnate to 

 sessile, often conglomerate, the disk flat to convex, black or rarely reddish brown, 

 the exciple of the same color, thin, often flexuous, finally disappearing; hypothe- 

 cium yellowish to reddish brown; spores 5-9-septate, 25-40 X 2-3 fi. 



On soil, moss, and rarely bark, New England and westward to Nebraska and 

 Minnesota. 



21. Bacidia Schweinitzii (Tuck.) Schneid., Guide Study Lich. 110. 1898. 

 Biatora Schweinitzii Tuck., in Dark, Fl. Cestr. ed. 3. 447. 1853. 



Thallus of rounded, often crowded or heaped granules, sometimes becoming 

 compacted and chinky-verrucose, greenish to olive-gray or ashy; hypothallus 

 finally blackening; apothecia middle-sized to rather large, 0.6-1.75 mm. across, 

 adnate to sessile, the disk flat to slightly convex, dark brown to black, the exciple 

 thick, of the same color or paler, often flexuous-lobulate; hypothecium yellowish 

 to dark brown; spores 7-15-septate, 40-70 X 2-3.5 jx. 



On trees, eastern United States, and westward to Texas and Minnesota. 



