Excerpt
LECIDEACEAE
Thallus crustose, without plectenchymatous cortex (, a), varying from granulose and often evanescent to conspicuous, areolate, or even subsquamulose conditions, attached to the substratum by hyphal rhizoids (, d), and in a few instances extending up as a veil and surrounding the apothecia laterally, the hyphae densely interwoven toward the upper surface, but more loosely disposed below (, a and b); apothecia usually minute or small, commonly rounded, the exciple weak and obscure (, d), or more strongly developed when conspicuous and much darker in color (, b); hypothecium varying from hyaline to dark brown (, b and , c); hymenium almost always lighter and commonly hyaline (Figs. and , a); paraphyses usually simple, but branched forms to be found frequently (Figs. and ), pale throughout or darkened toward the sometimes enlarged apex, commonly more or less coherent and indistinct at maturity; spores simple and hyaline to muriform and brown (Figs. , , , , , , , , and ).
KEY TO THE GENERA Spores minute, numerous in each ascus Biatorella, p. Spores larger, usually 8 in each ascus, Spores hyaline. Spores one-celled (simple) Lecidea, p. Spores more than one-celled (compound). Spores 2-celled Biatorina, p. Spores 4- to several-celled. Spores ellipsoid, fusiform, or dactyloid Bilimbia, p. Spores acicular Bacidia, p. Spores brown, or becoming brown. Spores 2-celled Buellia, p. Spores 4-celled and becoming muriform Rhizocarpon, p.Biatorella De Not. Giorn. Bot. Ital. 21. 192. 1846.
Thallus granulose to verrucose and subareolate, sometimes inconspicuous and evanescent; apothecia minute to middle-sized, adnate or more or less immersed, exciple usually prominent and persistent, but sometimes becoming covered, disk flat to convex; hypothecium and hymenium pale to brown; spores simple, hyaline, minute, numerous in each ascus.
KEY TO THE SPECIES OF BIATORELLA The whole apothecium dark colored 1. B. simplex The disk of the apothecium white-pruinose 2. B. pruinosa
1. Biatorella simplex (Dav.) Br. & Rostr. Bot. Tidssk. 3: 241 1869.
Lichen simplex Dav. Trans. Linn. Soc. Lond. 2: 283 pl. 28. f. 2. 1794.
Thallus thin and smooth or thicker and roughened, sometimes subareolate, ash-white to green-gray and darkening, rarely disappearing; apothecia minute to middle-sized, 0.2 to 0.8 mm. in diameter, adnate, scattered or crowded, rounded or variously irregular, black but usually dark red when damp, flat or slightly convex, the thin exciple raised and persistent; hypothecium light or darker brown; hymenium pale or tinged brown; paraphyses semi-distinct to coherent-indistinct; asci cylindrico-clavate; spores oblong-ellipsoid, 3 to 5 mic. long and 1 to 1.5 mic. wide.
Collected in Butler, Adams, Montgomery, Hocking, and Ross counties. On limestone. Not previously reported from Ohio, but probably frequent where there is limestone, though inconspicuous and easily overlooked.
2. Biatorella pruinosa (J.E....