THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 33 



0. Apothecia pear or top-shaped, growing on Pertusaria 



thallus, containing algae; spores simple . . .IX. Sphinctrina 



OO. Apothecia crateriform, not containing algae; spores 



bilocular, or simple in i form X. Cyphelium 



JJ. Apothecia without a mazaedium. 

 P. Apothecia usually linear or elongate, with a fissure-like disk; 



seldom circular; algae Trentepohlia. 

 Q. Thallus very, thin, uniform crustaceous. 

 R. Apothecia without margin, more or less stellate, branch- 

 ing, or irregular XII. Arthonia 



RR. i Apothecia with a margin. 



S. Apothecia innate, fissure-like, with evident disk; spores 



caterpillar-like, brown XIV. Phceographis 



SS. Apothecia sessile, not innate or fissure-like; apothecia 



irregular, linear or ellipsoid XIII. Opegrapha 



QQ. Thallus thick, irregular, of ten warty or sub-plicate; apothe- 

 cia circular or nearly so, with both proper and thalline 



margins XV. Dirina 



PP. Apothecia more or less circular and dish or shield-like; 

 never linear, though often angular or variously shaped 

 from pressure or crowding. 

 T. Algae blue-green (Cyanophycea) . 

 U. Algae Nostoc. 



V. Apothecia biatorine or lecideine. .XXXV. Parmeliella 



VV. Apothecia lecanorine XXXVII. Tannaria 



UU. Algae not Nostoc. 

 W. Algae Scytonema. 



X.^ Thallus squamulose to small-foliaceous, mostly 

 of parenchyma; spores simple, colorless. 



XXXIV. Heppia 



XX. Thallus crustaceous, coralloid, to small squamu- 

 lose, spores colorless, 2-8 locular. 



XXXVI. Placynthium 

 WW. Algae not Scytonema. 



Z. Algae Stigonema; thallus microscopically fruticose, 



of terete filaments XXVIII. Zahlbrucknera 



ZZ. Algae Glceocapsa; thallus diffract-crustaceous to 



minutely squamulose XXXI. Pyrenopsis 



TT. Algae not blue-green. 



a. Algae Trentepohlia XVII. Lecanactis 



aa. Algae Pleurococcus, Protococcus, or Palmella. 



b. Spores simple, colorless, minute, exceedingly numerous; thallus of 

 scales or squamules, with usually innate apothecia. 



XXVII. Acarospora 

 bb. Spores not excessively numerous. 

 c. Spores bi-locular, typically polari-locular, or becoming muri- 



form by interpolation of cross-walls. 

 d. Spores colorless, polar-bilocular. 

 e. Apothecia lecanorine LVEII. Caloplaca 



