226 



33. LECIDEACEAE [126. Bacidia 



22. Bilimbia trachona (Ach.) Trevis., Linnaea 28:293. 1856. 



Verrucaria trachona Ach., Meth. Lich. Suppl. 16. 1803. Biatora trachona (Ach.) 

 Koerb. Bacidia trachona (Ach.) Lettau. 



Thallus scurfy or granulose, greenish gray to ashy, becoming a thin, chinky 

 crust; apothecia small to middle-sized, 0.4-0.8 mm. across, adnate, the disk flat 

 to strongly convex, brownish black to black, the exciple entire and of same color, 

 often disappearing; hypothecium dark brown; spores fusiform-ellipsoid, 3-septate, 

 12-19 X 2.5-5.5 p. 



On shaded rocks, Massachusetts, New York, Ohio, Illinois, and Iowa. 



23. Bilimbia sabuletorum (Schreb.) Arm, Verh. Ges. Wien. 19:637. 1869. 

 Lichen sabuletorum Schreb., Spic. Fl. Lips. 134. 1771. Bacidia sabuletorum 



(Schreb.) Lettau. Biatora hypnophila (Ach.) Lonnr. Lecidea hypnophila 



Ach. B. hypnophila (Ach.) T. Fries. Bacidia obscurata (Sommerf.) Zahlbr. 



Thallus thin, greenish gray to ashy, of crowded granules, sometimes confluent, 



and forming a crust, or sometimes disappearing; apothecia small to middle-sized, 



0.2-0.7 mm. across, adnate to sessile, often clustered, the disk flat to strongly 



convex, light brown to black, the exciple black and soon disappearing ; hypothecium 



pale to darker brown; spores ellipsoid to fusiform, 3-7-septate, 15-30 X 4-7.5 /a. 



On moss and soil,, distributed throughout the United States. 



24. Bilimbia caudata (Nyl.) Fink n. comb. 



Lecidea caudata Nyl., Bot. Notis. 176. 1852. Bacidia lugubris (Sommerf.) 

 Zahlbr. 



Thallus moderately thick, granulose to chinky-areolate, brownish to ashy, on a 

 black hypothallus; apothecia small to middle-sized, 0.1-0.6 mm. across, sessile, the 

 disk flat to convex, black, the exciple of the same color, entire, becoming flexuous 

 or lobed, or finally disappearing; hypothecium brownish black; spores hyaline, 

 oblong-ellipsoid with caudate appendage, 3-7-septate, 30-45 X 4-6 /a. 



On rocks, White Mountains, New Hampshire. 



OTHER SPECIES REPORTED 



Bilimbia Meadii (Tuck.) — Biatora Meadii Tuck. — Florida. 



126. Bacidia De Not., Giorn. Bot. Ital. 2 1 :189. 1846. 



Thallus crustose, granulose, sometimes inconspicuous, rarely disappearing, often 

 passing into chinky, warty, subareolate, and even subsquamulose conditions, rudi- 

 mentary, usually devoid of differentiation, attached to the substratum by hyphal 

 rhizoids; apothecia usually adnate but sometimes sessile or rarely immersed, the 

 disk usually becoming convex, flesh-colored to more commonly darker or even 

 black, the exciple of the same color and usually becoming covered; hypothecium 

 usually yellowish to brown, but rarely persistently hyaline; hymenium hyaline to 

 brownish; paraphyses rarely branched; asci long-clavate to cylindrico-clavate ; 

 spores 8, hyaline, acicular, several-septate, the septa often indistinct, the cells 

 cylindrical. 



The algal host is Protococcus. 

 A. Hypothecium hyaline, yellowish to brown or rarely becoming darker 

 B. On rocks and rarely on wood 



C. Spores 3-7-septate, 1.5-3 /i in width 



D. Hypothecium hyaline to brown; spores 20-40 X 1.5-2.5 n 10. B. inundata 

 D. Hypothecium pale yellow; spores 18-30 X 2.5-3 ju ... 22. B.umbrina 



C. Spores 5-9-septate, 0.75-1.25 fi in width 8. B. egenuloidea 



B. On trees, old wood, and rarely on rocks 

 C. Spores rarely more than 40 /a in length 

 D. Hypothecium hyaline 



E. Thallus scaly or squamulose 



F. Spores 18-28 X 2-3 n 7. B. microphyllina 



F. Spores 30-40X1-S-2/* 6. B.Augustini 



