THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 33 



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



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



00. Apothecia crateriform, not containing alga;; spores 



bilocular, or simple in i form X. Cyphelium 



JJ. Apothecia without a mazasdium. 



P. Apothecia usually linear or elongate, w'ith a fissure-like disk; 

 seldom circular; algae Trenlepohlia. 

 Q. Thallus very thin, uniform crustaceous. 

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

 ing, or irregular XII. Arthonia 



RR. Apothecia with a margin. 



5". Apothecia innate, fissure-Hke, with evident disk; spores 



caterpillar-like, brown XIV. PhcBographis 



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. Pannaria 



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. Algffi Gloeocapsa; thallus diffract-crustaceous to 



minutely squamulose XXXI. Pyrenopsis 



TT. Algae not blue-green. 



a. Algae Trenlepohlia '. 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, topically polari-locular, or becoming muri- 

 form by interpolation of cross-walls. 

 d. Spores colorless, polar-bilocular. 



e. Apothecia lecanorine LVIII. Caloplaca 



