148 LICHENS OF THE STATE OF WASHINGTON 



thalHne margin present; hypothecium hyaline; paraphyses thick, un- 

 branched ; asci 8-spored ; spores hyaHne, nonseptate. 



A. Soft and flaccid, lobes flattened, angular. 



B. Lobes slightly pitted, often channeled near base, mealy sorediate, 



I. E. prunastri 

 B. Lobes deeply lacunose, densely beset with round to flat masses of 



soredia 2. E. prunastri var. sorediijera 



A. Rather stiff and rigid, lobes terete to subterete, angular. 



3. E. thamnodes 



1. Evernia prunastri (L.) Ach. Lichenogr. Univers. 442. 1810. 

 Lichen prunastri Linn. Sp. PI. 1147. 1753. 



Thallus tufted, olive-buff (R), grayish-olive (R), or Isabella color (R), 

 erect or pendulous, very much branched or irregularly dichotomously, 

 branches flattened, angular, pitted, often bearing mealy confluent soredia, 

 often channeled near the base, tips forked, specimens with wide branches 

 paler below. Apothecia rare, marginal, 2-6 mm. in diameter, subpedicellate ; 

 disk dark chestnut-brown (R), concave; thalline margin inflexed; spores 

 hyaline, short ellipsoid, nonseptate, 5.0-8.0 x 3.3-6.0 fi. 



On trees, shrubs, fallen branches, fences, and more rarely on rock: 

 Clallam Co.: Lake Sutherland, 590 ft., 1931, 1116; Cedarville, 300 ft., 

 1940, 2889. San Juan Co.: Shaw Island, 1928, 2088. Wahkiakum Co.: 

 Cathlamet, 1940, 2860. Thurston Co. : Grand Mound, 1940, 2976. Kitsap 

 Co. : Hidden Ranch near Bremerton, 213 ft., 1940, 3279. King Co. : Edge- 

 wood, 300 ft., 1940, 3082. Klickitat Co.: Goldendale, 2000 ft., 1931, 1700. 

 Whitman Co.: Tekoa Mountains, 1931, 2900 ft., 1606. Grays Harbor Co.: 

 Montesano, 1919, J. M. Grant 3022 (F). Snohomish Co.: Marysville, 

 1929, /. M. Grant (F). Spokane Co.: Biglowe Gulch, near Spokane, 1905, 

 T.A. Bonser (W). 



This lichen is easily recognized by the cottony medulla. It grows 

 abundantly in central Europe on oak trees, where it is called oak moss, and 

 is used as a base in the manufacture of perfumes. Grows on oaks in certain 

 regions of the state. Plate VII, C. 



2. Evernia prunastri var. sorediijera Ach. Lichenogr. Univers. 443. 1810. 



Thallus thicker, lobes shorter and broader, deeply lacunose and densely 

 beset with round to flat masses of soredia; otherwise like the species. 

 Sterile. 



On trees and fallen branches : San Juan Co. : San Juan Island, 1930, 

 504. Yakima Co. : Satus Road, 1054 ft., 1673. Clallam Co. : Dungeness, 

 \9U, Foster 2533 (W). 



3. Evernia thamnodes (Flw.) Arn. Verhandl. Zool.-Bot. Gesellsch. Wien. 



23:110. 1873. 

 Evernia prunastri var. thamnodes Flw. Die merk. und selten. Flecht. 

 Hirschberg. Warmbrunn 5. 1839. 



