20 LICHENS OF THE STATE OF WASHINGTON 



On old wood : Yakima Co. : Deadhorse Hill, 4000 ft., 1931, 971. Wash- 

 ington Territory, 1882, Suksdorf 173 (T). 



2. Xylographa hians Tuck. Syn. N. Am. Lich. 2:113. 1888. 



Thallus usually within the substratum, rarely showing on the surface, 

 as a grayish coloration. Apothecia 0.1-0.2 x 0.2-0.6 mm. in diameter, circu- 

 lar to oblong, adnate, clustered ; disk brown, concave to flat ; proper margin 

 thin, concolorous with the disk; spores hyaline, ovoid, nonseptate, 9.9-13.2 x 

 4.9-6.6 ti. 



On old wood: Grays Harbor Co.: Aberdeen, 1909, Foster (F). Wash- 

 ington Territory, Suksdorf 233 (T), Type specimen. 



10. Opegrapha Humb. Fl. Frib. Specim. 57. 1793. 



Thallus crustose, thin to slightly chinky or powdery, rarely disappearing 

 entirely within the substratum, no differentiation into layers ; apothecia 

 black, carbonaceous ; lirellae, linear to almost circular, immersed to adnate ; 

 proper margin well developed, thalline margin usually absent ; hypothecium 

 yellowish, brown, or black; paraphyses branched and interwoven; asci 

 cylindrical, thin walled, 8-spored ; spores hyaline, multiseptate. 



Alga Trentepohlia. 



A. Spores constantly 3-septate, surrounded by a thick gelatinous halo. 



4. O. protuberans 

 A. Spores 3-7-septate, not surrounded by a gelatinous halo. 



B. Spores constantly 3-septate 1. 0. atra 



B. Spores not constantly 3-septate. 



C. Spores always hyaHne. 2. O. diaphora 



C. Spores always hyaline, brown at maturity. 



D. Thallus smooth, apothecia subsessile 3. 0. lichenoides 



D. Thallus rough, apothecia immersed to adnate 5. O. varia 



1. Opegrapha atra Pers., Neu. Ann. Bot. Usteri 7 :30. 1794. 



Thallus white, thin, smooth, sometimes disappearing within the sub- 

 stratum. Apothecia spindle shaped, 0.2-3.0 x 0.2-0.4 mm., adnate, straight 

 or rarely curved ; disk black, usually closed, rarely narrowly opened ; proper 

 margin black ; hypothecium brownish black ; spores hyaline, ellipsoid larger 

 at one end, 3-septate, 15.2-19.0 x 4.0-5.7 /x,. 



On bark and old wood : Pierce Co. : Mt. Rainier White River Camp, 

 3900 ft., 1940, 3106a. Clallam Co. : Dungeness, 1913, Foster 2532 (F). 



This species can be distinguished by the rather long narrow apothecia. 



2. Opegrapha diaphora Ach. Meth. Lich. 19. 1803. Lichen diaphorus Ach. 

 Lich. Suec. Prodr. 20. 1798. Opegrapha varia var. diaphora Fries. 



Thallus gra}^ to greenish gray, smooth becoming rimose and sometimes 

 scurfy. Apothecia short and narrow, 0.2-1.0 x 0.1-0.3 mm., straight to fre- 



