THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 1 69 



Porina leioplaca Ach. Lich. Univ. 309, pi. 7. f. 2. 1810, 

 Pertusaria leioplaca Schaerer, Spicilegia, 66. 1823. 

 Pertusaria leioplaca Tuck. Syn. N. Am. Lich. I: 214. 1882. 



Thallus determinate, cartilaginous, thin to very thin, smooth, 

 becoming folded or undulate, and fissured; color whitish or creamy; 

 KOH yellow. 



Apothecial warts scattered, adnate, hemispherical to irregular, 

 smooth, somewhat flattened; ostioles soHtary or few, minute, punc- 

 tifomi, indistinct or blackening; spores varying, 3-4-5- and 6 in the 



asci; rarely only two; oblong ellipsoid; ^ /^. 



47 - 75 



On trunks and Hmbs of trees in the foothills. A cosmopolitan 



lichen. 



LECANORACEiE. 



Thallus crustaceous, uniform or marginally lobed, or exceptionally 

 fruticose, branched and decumbent; without rhizoids, and with or 

 without cortex; alga Protococcus or Pleurococcus. 



Apothecia permanently innate in the thallus or sessile, circular, 

 with a thalline margin enclosing algas; proper margin lacking or 

 imperfectly developed; hypothecium clear, usually upon a layer of 

 algae; paraphyses unbranched and free, or branched and agglutinate; 

 asci usually 8-spored, sometimes 2-8, or 8-32 sporous; spores color- 

 less, rarely brownish, simple, bilocular to multilocular and muri- 

 form; thin walled. 



KEY TO GENERA. 



A . Spores simple. 



B. Paraphyses unbranched, free. 



C. Spermatia thread-like, straight or curved . . .XLIII. Lecanora 

 CC. Spermatia eUipsoid, straight; thallus egg-yellow. 



XLVII. Candelariella 



BB. Paraphyses branched and net-hke XLIV. Ochrolechia 



A A. Spores not simple. 



D. Sterigmata exobasidial; spores bilocular. 

 E. Thallus gray or brown; spermatia thread-like, straight 



or curved XLV. Lecania 



EE. Thallus egg-yellow; spermatia ellipsoid, straight. 



XLVII. Candelariella 

 DD. Sterigmata endobasidial ; spores 2-4 locular. 



XL VI. Placolecania 



