tilaginous layer well defined. Primary squamules small, slender, finely incised, evanescent. K − or + f. C. pityrea. Soredia farinose; decorticate areas opaque or semipellucid 36 36. Lower part of podetia isidiose and sometimes squamulose also; 5–30 mm tall, scyphi present or absent, very narrow, shallow or deep; decorticate areas K + (pale yellow). Primary squamules broad, coarse, medium to large C. Borbonica. Podetia white, simple, 5–10 mm tall, mainly ecorticate and farinose sorediate; apex blunt or almost scyphose; base with coarse granules or minute squamules but scarcely isidiose; primary squamules 1 mm or less. Apothecia rare but large or small C. cylindrica. Lower part of podetia lacking isidia or large granules (except C. Balfouru) 37. 37. Podetia with continuous or areolate cortex almost to top, then sorediose; brown at base; 50–100 mm tall, cylindrical, subulate C. cornuta. Podetia wholly or mainly decorticate 38 38. Podetia usually taller than 25 mm 39. Podetia usually shorter than 25 mm 39 39. Scyphi rare, regular and repeatedly proliferous. Podetia more commonly simple or sparingly branched above, 30–65 mm tall, ascyphous; mainly decorticate and farinose-sorediose. P + C. cornutoradiata. Scyphi narrow and shallow, abortive, or absent; podetia elongate, 25–90 mm tall; often areolate-corticate at base, granular-sorediose above, branched. P ± C. nemoxyna. 40. Podetia decorticate save at base, densely sorediose, isidiose, ascyphous, unbranched; translucent cartilaginous layer often exposed; 5–25 mm tall. C. Balfourii. Podetia shortly corticate at base and apex, farinose-sorediate between, opaque 41 41. Corticate areas very short. Scyphi rare, small, narrow, or abortive; sorediose inside cups. Podetia usually simple, with truncate apices centrally depressed; 5–30 mm tall. Primary squamules rather large C. coniocraea. Corticate areas longer, with patches of cortex in sore diose area between; scyphi when present corticate within cup; podetia 5–40 mm tall; usually branched; apothecia usually yellowish-brown C. ochrochlora. 42. Primary thallus squamulose, often persistent. Podetia white, green, glaucous, or brownish; not intricately branched; axils open or closed; scyphi when present never closed unless partially by an annular membrane Subsection Chasmarae (43–51) Primary thallus squamulose, soon disappearing. Podetia yellowish, white, greenish or stramineous, usually corticate, scyphi and squamules rare; axils open or closed; plants much branched, dying at base Subsection Unciales (52–55). Primary thallus crustaceous, evanescent. Podetia ecorticate, ascyphous and esquamulose, ± tomentose; densely and intricately branched, forming dense or open white, yellowish, or glaucous-green cushions Subsection Cladinae (56–61) 43. Primary squamules medium to large, broad. K +, P + Series Megaphyllae (44). Primary squamules small, often narrow, evanescent Series Microphyllae (45–51). 44. Podetia 20–75 mm long, stout, branching, sometimes obsoletely scyphose; cortex ± areolate; esorediose; walls often perforate or fissured. P ±, C + C. turgida