THE LICHEN FLORA OF THE SANTA CRUZ PENINSULA 167 



4. PERTUSARIA WULFENII (DC.) E. Fr. 



Pertusaria wulfenii DeCandolle, Fl. Fr. 2: 320. 1805. 

 Pertusaria wulfenii E. Fries, Lich. Europ. Reform. 244. 1831. 

 Pertusaria wulfenii Tuck. Syn. N. Am. Lich. I: 216. 1882. 



Thallus determinate or becoming somewhat effuse, often orbicu- 

 late, sharply bounded by the black hypothallus, sometimes zonate 

 at the circumference; originally smooth but usually thick, rough, 

 fissured, and warty; sulfur-yellow and paler; yellow with KOH; 

 KOH + CaCl 2 2 orange-yellow. 



Apothecial warts usually crowded, sessile, flattened globose; 

 ostioles mostly confluent, forming a depressed black disk; the thai- 

 line margin thick, swollen, irregularly waved or folded; epithecium 

 violet with KOH; paraphyses and epithecium indigo with I; spores 



in eights, - p. 

 56 - 123 



Occurs with us on the bark of oaks, principally Quercus chryso- 

 lepis, at an altitude of 2000 feet and above. 



Widely distributed throughout the temperate zone, usually on 

 bark, rarely on stone. 



A very pale greenish gray to yellowish gray form occurs on Quer- 

 cus agrifolia along the Pacific shore, at an altitude of 50-200 feet; 



spores very much smaller, - - p. 



50 - 56 



5. PERTUSARIA VELATA (Turn.) Nyl. 



Parmelia velata Turner, Trans. Linn. Soc. 9: 143, pi 12, f i. 1808. 

 Pertusaria velata Nylander, Lich. Scand. 179. 1861. 

 Pertusaria lelata Tuck. Syn. N. Am. Lich. I: 212. 1882. 



Thallus thin, smooth, becoming chinky, somewhat zonate at the 

 circumference; color milk-white; KOH yellow; CaCl 2 2 . 



Apothecial warts small, adnate, lecanoroid, brownish red with 

 CaCl 2 2 ; disk plane or concave, concolorous to pale yellowish; 



40 60 



spores solitary, - /* 

 200 240 



A single specimen of this lichen has been found by me, growing on 

 the bark of an oak at Devils Canon, altitude 2300 feet. A common 

 plant of Europe, Asia, and North America. 



