192 33. LECIDEACEAE [119. Lecidea 



B. Hypothecium hyaline to dusky or yellowish or darker 

 C. Hypothecium hyaline to dusky 



D. Thallus thin, powdery 50. L. floridensis 



D. Thallus thicker, chinky- or squamulose-areolate 



E. Thallus grayish yellow to tan 55. L. atrolutescens 



E. Thallus pale yellowish to yellowish red 54. L. armeniaca 



C. Hypothecium tinged yellowish or darker 

 D. On trees or old wood 



E. Thallus greenish gray to yellowish or bright yellow . . 53. L. aitema 



E. Thallus dark ashy to whitish 59. L. parasema achrista 



D. On rocks 



E. Hypothecium hyaline to yellowish 



F.' Spores 10-12 X 2-3 .5 fM 52. L. Hassei 



F. Spores 12-17 X 6-9 ft 51. L. catalinariae 



E. Hypothecium yellow to blackish . . . . 59. L. parasema theioplaca 

 B. Hypothecium hyaline to brownish or brown 



C. Thallus greenish gray to ashy, whitish, or yellowish 

 D. Apothecia solitary and scattered 



E. Black hypothallus not conspicuous 



F. Thallus very thin to thin, smooth to chinky and 

 finally areolate 

 G. Apothecia rarely less than 0.5 mm. across 



H. Apothecia yellowish to blackish and obscurely 



grayish pruinose 59. L. parasema ambigua 



H. Apothecia black 59. L. parasema 



G. Apothecia rarely more than 0.5 mm. across . 61. L. virginiensis 



F. Thallus moderately thick 68. L. pantherina 



E. Black hypothallus conspicuous 



F. Thallus greenish white to ashy gray 



G. Thallus very thin, scurfy 62. L. cruciaria 



G. Thallus moderately thick, granulose to warty- 



areolate 67. L. panaeola 



F. Thallus yellowish 59. L. parasema flavens 



D. Apothecia more or less clustered or confluent 

 E. On rocks, soil, and over moss 



F. On soil and over moss 59. L. parasema muscorum 



F. On rocks 



G. Spores rarely more than 15 fi in length 

 H. Black hypothallus usually conspicuous 



I. Exciple lighter colored than the disk . . 57. L. pruinosa 

 I. Exciple same color as the disk 



J. Thallus chinky-areolate, greenish gray 



to ashy . . 58. L. polycarpa 



J. Thallus squamulose-areolate, yellowish to 



copper or chestnut-brown . . . 104. L. atrobrunnea 

 H. Black hypothallus not conspicuous 



I. Disk flat to strongly convex 64. L.pacifica 



I. Disk slightly concave to slightly convex . 63. L. lithophila 

 G. Spores rarely less than 15 /j. in length 



H. Disk black 56. L. Brujeriana 



H. Disk thinly gray-pruinose 69. L. arctica 



E. On old wood 



F. Thallus more or less granulose 



G. Thallus thin, granules sometimes forming 



a thin crust 65. L. viridescens 



G. Thallus thicker, granules more often forming 



a crust 66. L. gelatinosa 



F. Thallus smooth to slightly rough 60. L. torquens 



C. Thallus greenish gray to olive-brown, or reddish brown to 



darker, squamulose 70. L. lugubris 



B. Hypothecium brownish to brown and black 

 C. Thallus soon disappearing 



D. Spores rarely more than 10 p. in length 74. L. micytho 



