THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 247 



On rocks near Mayfield, at an altitude of 200 feet, and on jasper 

 at Twin Peaks, San Francisco, altitude about 550 feet. 

 This species seems to be almost as near Rhizocarpon as to Buellia. 



LXII. Rinodina (Mass.) Stiz. 



Rinodina Mass. Ric. Lich. Crost. 14. 1852. 



Rinodina Stizenberger, Beitrag zur Flechtensystematik, 45. 1862. 



Thallus crustaceous, rarely squamulose, uniform or marginally 

 lobed, without rhizoids, a cortex present in some species; alga Pro- 

 tococcus. 



Apothecia circular, innate or sessile, lecanorine, with thalline mar- 

 gin enclosing algae which in some species soon die; proper margin 

 very thin or lacking; disk dusky or black, naked or pruinose; epithe- 

 cium granular or powdery, usually purple or violet with KOH; hypo- 

 thecium colorless, rarely dark; paraphyses simple or rarely forked, 

 thread-like, more or less clavate, often thickened at the tips; spores 

 usually 8, rarely as many as 24, smoky gray, brown, or blackish, 

 2-4 celled, with (usually) strongly thickened walls, the cell contents 

 united by an isthmus. 



A large genus of rock and bark lichens, found all over the world. 



KEY TO THE SPECIES. 



A. Thallus obsolete or nearly so, on limestone; apothecia im- 

 mersed in pits in the rock 3. bischoffi immersa 



AA. Thallus well developed. 



B. Thallus with margin radiately lobate. 



C. Thallus white to dusky gray i. radiata 



CC. Thallus greenish yellow or straw-color 2. oreina 



BB. Thallus not marginally lobate. 



D. On rocks. 



E. Thallus dark brownish to olive black ; KOH ... 4. tephraspis 

 EE. Thallus whitish to brown-gray ; KOH bright yellow 



5. confragosa 

 DD. On bark. 



F. Thallus brown or gray. 

 G. Color umber or dark brown; apothecia often 



pruinose 6. hallii 



GG. Color olive-brown or gray-brown; apothecia 



never pruinose 7. sophodes 



FF. Thallus whitish or gray. 



H. Thallus reddish with CaCl 2 O 2 8. atrocinerea 



EE. Thallus not affected by CaCl 2 O 2 . 



