THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 79 



L. Thallus yellow or sulfur -colored; hypothecium dark 

 brown ............... .... 23. enter oleuca theioplaca 



LL. Thallus whitish gray, ashen, or bluish-gray. 

 M. Yellow with KOH. 



N. Hypothecium thick, brown. Hymenium blue, then 

 brown with 1 ...................... 21. latypaa 



NN. Hypothecium colorless to dusky; hymenium 

 blue with 1 .................... 22. enteroleuca 



MM. Thallus without reaction to KOH. 



O. Without evident hypothallus, ash-colored or leaden 

 gray; apothecia small .......... 15. platycarpa 



OO. A black hypothallus more or less evident. Apo- 



thecia from small or medium to very large. 

 P. Apothecia more or less gray pruinose; thallus 

 ash-colored ................ 12. lithophila 



PP. Apothecia not pruinose. 

 Q. Thallus ashy-gray or whitish ____ 13. tessellata 



QQ. Thallus bluish-gray or gray ... 14. lapicida 



i. LECIDEA DECIPIENS (Ehrh.) Ach. 



Lichen decipiens Ehrhart, Hedwig Stirpes Crypt. 2:7. 1789. 



Lecidea decipiens Ach. Meth. Lich. 80. 1803. 



Biatora decipiens Tuck. Syn. N. Am. Lich. II: 13. 1888. 



Thallus of scattered to crowded, rather thin, appressed, smooth 

 scales of medium size; often shield-shaped or round-lobed and cre- 

 nate; more or less concave or furrowed, sometimes plicate; of a 

 bright reddish flesh-color, brick-red, or darkening; the margin more 

 or less white-edged; beneath white; with KOH the thallus is first 

 rose pink, than a plum color; CaCl202 . 



Apothecia small to rather above medium size, usually marginal 

 but also occurring in the middle of a scale, closely adnate, from cir- 

 cular becoming angular in shape; the black disk soon convex; gener- 

 ally the small, paler margin is hardly visible and soon entirely disap- 

 pears; occasionally it is white and persistent; paraphyses conglu- 

 tinate, their tips umber; hypothecium clear to pale brown; asci 

 narrowly clavate; thecium blue with I; spores ellipsoid or ovoid, 



9.5 - 16 



On earth in lime rock crevices, near the summit of Black Moun- 

 tain, at an altitude of 2700 feet, mingled with Toninia caeruleo-nigri- 

 cans and Dermatocarpon hepaticum. 



