106 LICHENS OF THE STATE OF WASHINGTON 



On rock : Yakima Co. : Naches, gulch near Gleason's Ranch, 1350 ft., 

 1931, 908a, type specimen (W). Chelan Co.: Beaver Summit, 2800 ft.. 

 1940, 3353. 



21. PERTUSARIACEAE 



Thallus uniformly crustose, normally superficial, seldom developed 

 within the substratum, upper cortex present or absent, algal layer and 

 medulla well developed, but lower cortex lacking, attached to the sub- 

 stratum by hyphal rhizoids. Apothecia circular, 1 -several in each apothe- 

 cial wart, immersed ; proper margin lacking, thalline margin present ; asci 

 1-8-spored ; spores hyaline or brown, usually large and thick walled, non- 

 septate or 1 -septate. 



Alga Protococcus. 



45. Pertusaria DC. in Lam. & DC. Fl. Franc. 3rd ed., 2 :319. 1805. 



Thallus crustose, thin or thick, usually superficial, seldom partly within 

 the substratum, with a poorly developed plectenchymatous upper cortex, 

 well developed algal layer and medulla, and lower cortex lacking. Apothecia 

 1 -several in each wart, circular, to globular, immersed; thalline margin 

 breaking up into a soredial mass, or firm and well developed. Apothecia 

 opening by a small ostiole or forming a typical disk ; hypothecium hyaline ; 

 paraphyses branched, interwoven to form a net, asci 1-8-spored; spores 

 usually hyaline, rarely brown, large or very large, thick walled, nonseptate. 



A. Thallus bearing many heaps of white soredia. 



B. Thallus sterile, tastes bitter, like quinine 1. P. amara 



B. Thallus not always sterile, has no quinine taste. 4. P. multipimcfa 



A. Thallus not bearing many heaps of white soredia, if present, not abun- 

 dant. 



C. Thalline margin thick, regular, rarely disappearing, spores large, often 



more than 200 ju, long. 6. P. velata 



C. Thalline margin thin, irregular, sometimes disappearing. 

 D. Disk prominent, well developed. 



E. Disk black, asci usually 2-spored 5. P. pustulata 



E. Disk not black, asci 8-spored 2. P. ambigens 



D. Disk absent, indistinct black ostioles present. 3. P. leioplaca 



1. Pertusaria amara (Ach.) Nyl. Bull. Soc. Linn. Normandie ser. 2. 

 6:288. 1872. 

 Variolaria amara Ach. Kgl. Vetensk. Akad. Nya Handl. 163. 1809. 



Thallus light yellowish olive (R) or grayish white, becoming widely 

 spread, rough and cracked, somewhat powdery, bearing numerous heaps 

 of white soredia, which are often confluent, margins zonate. Apothecial 

 warts adnate, flat, sterile; thalline margin irregular, these warts develop 

 into the powdery soredial heaps, that almost cover the central part of the 

 thallus. These apothecial warts taste bitter like quinine ; yellow then reddish 

 with KOH, violet with KOH + CaOCl,. 



