294 " 38. LECANORACEAE [ 142. Lecanora 



apothecia small to large, immersed to adnate or sessile, the disk flat to convex, the 

 exciple colored like the thallus; hypothecium hyaline to brownish; hymenium 

 hyaline or brownish above; paraphyses unbranched; asci clavate; spores 2-8 or 

 rarely 16-32, hyaline, non-septate. 

 The algal host is Protococcus. 



A. Thallus dwarfish-fruticose 



B. Thallus pale or greenish straw-colored 



C. Apothecia 0.5^ mm. across, disk flesh-colored to 



yellowish and brownish 66. L. Bolanderi 



C. Apothecia 0.6-1.5 mm. across, disk pale yellowish to 



tawny red 67. L. thamnitis 



B. Thallus reddish yellow or lighter 68. L. phryganitis 



A. Thallus crustose to more or less foliose 



B. Thallus foliose or more or less lobed, at least toward 

 the circumference 

 C. Thallus foliose or squamulose 

 D. Apothecia present 



E. Apothecia large, 1.5-5 mm. across 



F. Thallus smooth to rough 63. L. rubina 



F. Thallus chinky and wrinkled .... 63. L. rubina heteromorpha 

 E. Apothecia smaller, rarely more than 2.5 mm. across 



F. Thallus foliose, attached by an umbilicus . . . 53. L. marginalis 



F. Thallus squamulose 49. L. thamnoplaca 



D. Apothecia unknown 65. L. Haydenii 



C. Thallus areolate or squamulose toward the circumference 

 D. Apothecia immersed to adnate 



E. Spores 8, rarely more than 16 m in length 

 F. Apothecia 0.3-0.8 mm. across 



G. Disk olive-brown to blackish 50. L. intricata 



G. Disk buff to darker brownish 56. L. versicolor 



F. Apothecia 0.6-1.5 mm. across 



G. Disk light to dark brown 55. L. circinata 



G. Disk flesh-colored to livid black, usually 



whitish pruinose 54. L. rupicola 



E. Spores 4-10, 14-24 X 9-20 fi 52. L. glaucopsina 



D. Apothecia adnate to subsessile or sessile 

 E. Disk more or less pruinose 



F. Thallus ashy to whitish or light brown to brownish 



G. Thallus pruinose in scattered areas ... 64. L. bipruinosa 



G. Thallus not pruinose 51. L. melanaspis 



F. Thallus straw-colored, dull greenish gray to 

 sulphur-yellow 



G. Thallus sulphur-yellow within 60. L. pinguis 



G. Thallus whitish within 62. L. semitensis 



E. Disk not pruinose 



F. Thallus not pruinose 



G. Disk light-colored to darker or black 



H. Apothecia adnate, disk concave to flat 

 I. Thallus pale greenish gray to whitish, 



bearing soredia 61. L.gelida 



I. Thallus greenish gray to yellowish 



brown 48. L. melanophthalma 



H. Apothecia adnate to subsessile or sessile, 

 disk flat 



I. Thallus greenish gray to yellowish or 

 rarely brownish 



J. Thallus long- or shorter-lobed ... 57. L. muralis 

 J. Thallus lobes elongated . . 57. L. muralis Garovaglii 

 I. Thallus more or less brownish . . 57. L. muralis saxicola 

 G. Disk reddish brown or brown to black 

 H. Thallus greenish gray to ashy or 



yellowish 47. L. frustulosa 



H. Thallus yellowish brown to reddish and 



darker 58. L. diffracta 



