264 34. CLADONIACEAE [ 132. Cladoma 



52. Cladonia gracilescens (Floerke) Vainio, Act. Soc. Faun. Flor. Fenn. 10:159. 



1894. 



Capitularia gracilescens Floerke, Ges. Naturf. Freund. Mag. 4:321. 1810. 



Primary thallus rarely persistent, composed of middle-sized, subentire to 

 slightly lobed and crenate, flat, scattered, greenish gray to rarely greenish brown 

 squamules; white below; podetia arising from squamules of primary thallus. 

 elongated, cylindrical, often hollow, crowded and forming dense clusters, erect 

 or ascending, more or less branched toward the apex, the sides subentire or 

 becoming more or less fissured, cortex subcontinuous or areolate, the areoles 

 elevated and irregular, squamulose, colored like the primary thallus; cups more 

 or less regular, gradually or rather abruptly dilated, the cavity deep, the center 

 and rarely the margin repeatedly proliferate; apothecia small to middle-sized, 

 0.5-1.5 mm. across, borne on short stalks on the margin of the cups, the disk 

 flat to convex, dark brown or rarely reddish brown. 



On soil, New Hampshire and Colorado. 



53. Cladonia pyxidata (L.) Hoffm., Deutschl. Fl. 2:121. 1795. 



Lichen pyxidatus L., Sp. PI. 2:1151. 1753. CI. pyxidata var.neglecta (Floerke) 

 Mass. CI. pyxidata var. chlorophaea (Spreng.) Floerke. CI. pyxidata i.cos- 

 tata Floerke. CI. pyxidata var. chlorophaea f . lepidophora Floerke. 



Primary thallus commonly persistent, composed of irregularly or digitately 

 incised or lobate, flat, concave, or rarely convex, commonly ascending, clustered 

 or scattered, greenish gray to whitish or greenish squamules; lighter and sorediate 

 below; podetia arising from the primary thallus, top-shaped and often hollow, 

 erect, closely clustered, the cortex areolate or verrucose or subcontinuous toward 

 the base, sometimes decorticate and sorediate toward the top, rarely more or less 

 squamulose, greenish gray to ashy or olive-green; cups regular or irregular, gradu- 

 ally or abruptly dilated, the cavity sorediate or corticate, the margin dentate or 

 proliferate; apothecia middle-sized, 1-4 mm. across, solitary to conglomerate, 

 sessile or shortly stalked on the margin of the cups, the disk flat to convex, brown. 

 (Plate 21.) 



On soil or rotten wood, throughout the United States. 



var. pocillum (Ach.) Flot., Linnaea 17:19. 1843. 



Baeomyces pocillum Ach., Meth. Lich. 336. pi. 8, f. 6. 1803. 



Primary thallus composed of thick, round-lobed or incised, closely adnate or 

 slightly ascending, more or less imbricated squamules, closely packed into a 

 greenish or brownish crust; podetia commonly sterile. 



On soil, throughout the United States. 



54. Cladonia mateocyatha Robbins, Rhodora 27:50. 1925. 



Primary thallus persistent or disappearing, composed of middle-sized to large, 

 elongated, entire to crenate, usually ascending, greenish gray or olive-green 

 squamules ; white or sordid below ; podetia arising from the primary thallus, short, 

 0.5-3 cm. long, erect, rather slender to stout, enlarged at the apex to form the 

 cup, the cortex continuous or areolate, smooth to slightly roughened, greenish 

 gray to olivaceous or darker; cups imperforate, narrow to rather broad, shallow, 

 simple to several-ranked, proliferations usually from the sides of the cups, rarely 

 central, the apices usually terminated by apothecia; apothecia small to middle- 

 sized, 0.5-1 mm. across, usually round, the disk convex, pale brown to dark brown. 



On soil, Massachusetts, Connecticut, and the District of Columbia. 



55. Cladonia verticillata Hoffm., Deutschl. Fl. 2:122. 1796. 



CI. verticillata var. evoluta T. Fries. CI. verticillata f. phyllocephala Oliv. 



Primary thallus commonly persistent, composed of middle-sized or larger, 

 irregularly subcuneate or crenately lobed, or even incised-lobate, flat or somewhat 

 inward-rolled, ascending, clustered or scattered, greenish gray to ashy, olive, or 

 brownish squamules; white below or darkening toward the base; podetia arising 

 from the primary thallus, hollow and rarely turbinate, subsolitary or clustered 



