216 33. LECIDEACEAE [121. Nesolechia 



mm. across, sessile, sometimes clustered, the disk flat to strongly convex, brown 

 to black, the exciple lighter and soon disappearing; hypothecium brownish to 

 brown; hymenium hyaline to yellowish; spores ovoid-ellipsoid, 9-14 X 5-6.5 /x. 



On soil, Vermont, Michigan, Montana, Arizona, California, Oregon, and Wash- 

 ington. 



121. Nesolechia Mass., Misc. Lich. 13. 1856. 



Thallus imbedded in that of the host and therefore invisible; apothecia minute 

 to small, immersed to adnate or sessile, the disk flat to more or less convex, the 

 exciple colored like the disk, thin, soon disappearing; hypothecium hyaline or 

 brownish to brown; hymenium hyaline or brownish above; paraphyses branched, 

 often swollen toward the apices, becoming coherent; asci clavate; spores 8, hya- 

 line, ovoid, ellipsoid to fusiform, non-septate. 



The algal host is Pleurococcus or Protococcus. (Zahlbruckner and Lindau omit 

 from lichen classification, regarding these as non-lichen fungi.) 



A. Spores less than 15xi in length 



B. Disk yellowish flesh-colored 4. N. Papillariae 



B. Disk black 



C. Spores 9-12 /a in length 



D. Exciple moderately thick; spores 9-11 X 6.5-7 n ... 3. N. vitellinaria 

 D. Exciple inconspicuous; spores 9-12 X 3-4.5 /a . . . 5. N. cladoniscum 



C. Spores 6-8 X 2-3 fi 2. N. oxysporella 



A. Spores 15-20 X 5-7.5 /i 1. N. oxyspora 



1. Nesolechia oxyspora (Tul.) Mass., Misc. Lich. 13. 1856. 



Abrothallus oxysporus Tub, Ann. Sci. Nat. Bot. III. 17:116. pi. 16, f. 27. 1852. 

 Lecidea oxyspora (Tul. ) Nyl. Biatora oxyspora (Tul.) Tuck. 



Thallus disappearing or not distinguishable from that of the host, the latter 

 deformed by the parasite and passing into small tufts of hemispherical or irregular 

 lobules; apothecia minute, 0.16-0.3 mm. across, more or less immersed in the de- 

 formed thallus of the host, the disk flat to slightly convex, pale brown to black, 

 the exciple disappearing; hypothecium pale brownish to brown; spores ellipsoid to 

 fusiform, 15-20 X 5-7.5 /x. 



On species of Parmelia, especially Parmelia borreri, on trees, New England to 

 Minnesota. 



2. Nesolechia oxysporella (Nyl.) Arm, Flora 57:99. 1874. 



Lecidea oxysporella Nyl., Enum. Lich. 127. 1850. N.punctum Mass. 



Thallus imbedded in the host and invisible; apothecia very minute, 0.05-0.15 

 mm. across, partly immersed to adnate, the disk strongly convex, black, the exciple 

 disappearing and seldom seen; hypothecium brownish; paraphyses slender, 

 branched, often swollen toward the tips; asci clavate; spores ellipsoid, 6-8 X 2-3 /x. 



On species of Cladonia, Iowa. 



3. Nesolechia vitellinaria (Nyl.) Rehm, in Rabenh., Krypt. Flora 1*:318. 1890. 

 Lecidea vitellinaria Nyl., Bot. Not. 1852:177. 1852. 



Thallus wholly or for the most part imbedded in host and invisible, possibly 

 sometimes scantily developed superficially; apothecia minute to small, 0.1-0.4 mm. 

 across, sessile, the disk concave to flat, black, the exciple moderately thick, black, 

 slightly elevated; hypothecium brownish to brown; spores ellipsoid or oblong- 

 ellipsoid, 9-11 X 6.5-7 /x. 



On the thallus of Candelariella vitelline, Colorado. 



4. Nesolechia Papillariae (Willey) Fink n. comb. 



Biatora Papillariae Willey, Enum. Lich. New Bedford, Mass. 22. 1892. 



Thallus mostly within the lichen host, appearing as grayish areas; apothecia 

 very minute, 0.06-0.1 mm. across, the disk convex, yellowish flesh-colored, the 

 exciple disappearing; hypothecium hyaline; spores ellipsoid, 5-10 X 2-3.5 /x. 



On podetia of Cladonia Papillaria, near New Bedford, Massachusetts. 



