296 38. LECANORACEAE [ 142. Lecanora 



F. Thallus greenish ashy to olive-green or brown 

 G. On rocks 



H. Thallus thin, greenish ashy to olive-green . . 43. L. badia 

 H. Thallus thicker, coppery or duller brown . 44. L. atriseda 



G. On trees 46. L.phaeobola 



E. Apothecia light-colored to becoming brownish or black 

 F. Apothecia yellowish, flesh-colored, or orange to 

 rarely pale brown 

 G. On trees and rarely on rocks 

 H. Disk more or less pruinose 

 I. Apothecia 0.7-3 mm. across 

 J. Apothecia sometimes smaller 



K. Apothecia crowded and irregularly 



angular 35. L. pallida angulosa 



K. Apothecia scattered 35. L. pallida 



J. Apothecia larger 



K. Apothecia becoming pro- 

 liferate 35, L. pallida prolif era 



K. Apothecia swollen, exciple crenate 



and lobed 35. L. pallida cancriformis 



I. Apothecia 0.5-0.8 mm. across . . . . 37. L. orosthea 

 H. Disk not pruinose 



I. Thallus greenish gray 34. L. cupressi 



I. Thallus pale greenish, yellowish, or 



whitish 39. L. varia 



G. On rocks 



H. Apothecia 0.5-1.5 mm. across 



I. Apothecia crowded, irregular . 41. L. polytropa alpigena 



I. Apothecia scattered 41. L. polytropa 



H. Apothecia smaller, 0.3-0.7 mm. 



across 41. L. polytropa illusoria 



F. Apothecia pale yellow, flesh-colored, red or 

 brownish, or darkening 



G. On trees, old wood, moss, and rarely on rocks 

 H. Spores 8 in an ascus 



I. Apothecia 0.1-0.25 mm. across 



J. Spores 3-5X2-3/* 18. L. minutella 



J. Spores 8-12X4-5.5 /* 32. L. piniperda 



I. Apothecia usually more than 0.2 mm. across 

 J. Disk more or less pruinose 



K. Spores 7-14X4-6/* 28. L. Hageni 



K. Spores 12-16X6.5-10/* . . . 27. L.pacifica 

 J. Disk not pruinose 



K. Thallus more or less granulose 



L. On old wood 40. L. symmicta 



L. On moss . . . . 26. L. subfusca hypnorum 

 K. Thallus chinky or warty to areolate 



L. Thallus sorediate . 26. L. subfusca variolosa 



L. Thallus not sorediate 



M. Spores 11-20 X 7-10/* 

 N. Disk flat to somewhat 



convex 26. L. subfusca 



N. Disk strongly and irregularly 



convex ... 26. L. subfusca campestris 



M. Spores 8-15 X 5-8 /* 



26. L. subfusca argentata 



H. Spores 8-32, usually 12-16 in an ascus 



I. Disk flat to convex 29. L. Sambuci 



I. Disk broken into 2-8 convex 



areas 29. L. Sambuci minnesotensis 



G. On rocks 



H. Disk light-colored to darker 

 I. Spores 10-17X5-8.5/* 



J. Disk thinly pruinose 24. L. cenisia 



