THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 37 



GG. Thallus yellow. 



/. Spores simple, colorless; thallus bright lemon-color; apothe- 



cia chestnut LIII. Letharia 



II. Spores polar-bilocular, colorless; plants and apothecia 

 reddish yellow or orange. 

 /. Thallus erect, lax, pendulous or decumbent; on trees and 



maritime rocks LX. Theloschistcs 



J J. Thallus short, rigid, becoming decumbent; on mari- 

 time rocks LVIII. Cahplaca 



FF. Plants gray, green, or pale. 

 K. Apothecia present. 



L. Apothecia concolorous; thallus tufted, compressed or 

 terete, or elongate, pendulous, and greatly compressed. 



LV. Ramalina 

 LL. Apothecia not colored like thallus. 



M. Apothecia black, pruinose or naked; thallus mar- 

 ginally fibrillose and fuzzy . .LXIY. Anaplychia 

 MM. Apothecia not pruinose or black. 



N. Apothecia chestnut; lobes long, ascendant, white 



beneath, on trees L. Celraria 



NN. Apothecia yellowish or dusky; plants very short, 

 stout, erect, rigid, sub-crustaceous; on maritime 



rocks XLIII. Lecanora 



KK. Apothecia absent. 



0. Lobes narrow, ascendant, margined with stout, usually 



branching fibrils LXIV. Anaptychia 



00. Lobes not marginally fibrillose. 



P. Sub-crustaceous; short, stout, terete; powdery, simple 



or branched; on maritime rocks . .XLIII. Lecanora 



PP. Thallus pendulous or erect ; more or less white sorediate ; 



on trees and shrubs LII. Evernia 



LICHENES. 



ASCOLICHENES. 



Composed of Fungi belonging to the Ascomycetes, living in union 

 (symbiosis ?) with Algae, these two distinct classes of plants apparently 

 forming a morphological and physiological unit. 



I. Pyrenocarpe^: Apothecia globular, usually opening at the 

 summit by a minute pore. 



II. Gymnocarpe^: Apothecia more or less open and the disk 

 exposed, circular and shield-like or dish-like, elongated and variously 

 shaped, or crater-like. 



