126. Bacidia] 33. LECIDEACEAE 231 



22. Bacidia umbrina (Ach.) Branth & Rostr., Bot. Tidssk. 3:235. 1869. 

 Lecidea umbrina Ach., Lich. Univ. 183. 1810. Biatora umbrina (Ach.) Tuck. 



Biatora umbrina var. compacta (Koerb.) T. Fries. 



Thallus of minute granules, usually flattened, thickish and continuous, or 

 thinner and scattered, often becoming scurfy, chinky, or subareolate, greenish gray 

 or ashy to blackish, sometimes disappearing; apothecia minute to small, 0.25-0.6 

 mm. across, partly immersed to adnate, the disk flat to convex, light brown to 

 black, the exciple paler, soon disappearing; hypothecium pale yellow; spores 3-7- 

 septate, 18-30 X 2.5-3 fx. 



On rocks, and rarely on wood, widely distributed throughout northern United 

 States, southward to North Carolina, and westward to California. 



23. Bacidia chlorosticta (Tuck.) Schneid., Guide Study Lich. 109. 1898. 

 Lecidea chlorosticta Tuck., Proc. Am. Acad. 5:419. 1862. Biatora substipitata 



Stizenb. Biatora chlorosticta Tuck. 



Thallus of minute, smooth, greenish to ashy granules, thinly scattered, or 

 crowded and forming a rough granulose crust; apothecia minute, 0.1-0.3 mm. 

 across, raised-sessile to short-stipitate, usually clustered, the disk convex, pale 

 lead-colored to black, the exciple evanescent; hypothecium blackish brown; spores 

 1-3-septate, 18-29 X 1.3-2.2 fi. 



On trees, Massachusetts, South Carolina, and Illinois. 



24. Bacidia endocyanea (Tuck.) Zahlbr., Cat. Lich. Univ. 4:192. 1926. 

 Biatora endocyanea Tuck., in Willey, Enum. Lich. New Bedford, Mass. 24. 



1892. 



Thallus thin and inconspicuous, greenish gray; apothecia minute to small, 0.15- 

 0.55 mm. across, the disk soon strongly convex, brownish black to black, the 

 exciple disappearing very soon; hypothecium dark brown to blackish; hymenium 

 bluish; asci narrowly clavate; spores 3-5-septate, 22-35 X 2.5-4 fi. 



On holly, near New Bedford, Massachusetts. 



25. Bacidia incompta (Borr.) Anzi, Cat. Lich. Sondr. 70. 1860. 



Lecidea incompta Borr., in Sowerby, Engl. Bot. Suppl. 2: pi. 2699. 1834. Bia- 

 tora incompta (Borr.) Hepp. Biatora luteola var. incompta (Borr.) Tuck. 



Thallus minutely granulose, thin, smooth, and powdery, to thicker, wrinkled, 

 and subareolate, greenish gray; apothecia minute to small, 0.35-0.75 mm. across, 

 adnate, the disk flat to convex, brownish black to black, the exciple of the same 

 color, thin, flexuous, finally disappearing; hypothecium reddish brown; spores 

 3-7-septate, 17-32 X 2-3 li. 



On trees, New England, and westward to Illinois and Minnesota. 



26. Bacidia Jacobi (Tuck.) Hasse, Cont. U.S. Nat. Herb. 17:51. 1913. 

 Biatora Jacobi Tuck., Syn. N. A. Lich. 2:48. 1888. 



Thallus scurfy or powdery, widespread, white to ashy gray, becoming some- 

 what rough and finally verrucose ; apothecia minute to small, 0.2-0.6 mm. across, 

 adnate, the disk flat to slightly convex, black, the exciple also black, thin and often 

 disappearing; hypothecium blackish brown; spores 3-7-septate, 20-38 X 2-3.5 ll. 



On trees, California. 



27. Bacidia abductans (Nyl.) Zahlbr., Cat. Lich. Univ. 4:166. 1926. 

 Lecidea abductans Nyl., Lich. Jap. 68. 1890. 



Thallus very thin to thin, composed of minute granules forming a chinky, 

 smooth to warty, ashy crust; apothecia small to middle-sized, 0.5-1 mm. across, 

 adnate to sessile, the disk flat to strongly convex, dull brownish black to black, 

 the exciple thin, black, soon disappearing; hypothecium brown; spores 8, acicular, 

 5-9-septate, 48-60 X 3-3.5 fx. 



On trees, Florida. 



