LICHENS OF THE STATE OF WASHINGTON 125 



Thallus greenish yellow (R), bright yellow, or ashy white, small, sub- 

 orbicular or spreading, lobes small, laciniate crenate, or somewhat imbri- 

 cated, often forming a continuous crust, near the center, granulose, soredi- 

 ate, or isidiose; below pale, ashy, with rhizoids. Apothecia very small, 

 scattered, circular, 0.2-0.8 mm. in diameter, sessile ; disk orange, yellow, or 

 yellowish brown, concave to flat; thalline margin concolorous with the 

 thallus, entire to slightly granulate; hypothecium hyaline; asci 20-60- 

 spored; spores hyaline, oblong, nonseptate, or imperfectly 1 -septate, 

 9.3-12.4 X 2.0-4.5 fx. 



On trees, stumps, or rock: Kittitas Co. : South Cle Elum, 3000 ft., 1931, 

 860. Chelan Co.: Merritt, 2186 ft., 1931, 1085a; butte near Chelan, 2000 

 ft, 1931, 1326a. 



53. Parmeliopsis Nyl, Syn. Lich. 2 :53. 1863. 



Thallus foliose, small, thin, appressed, upper cortex loosely and irregu- 

 larly plectenchymatous, lower cortex typical and well developed, rather 

 irregular algal and medullary layers; attached to the substratum by scat- 

 tered rhizoids, Apothecia rare, small to medium sized, scattered, sessile; 

 thalline margin present; hypothecium hyaline to pale brown; paraphyses 

 rarely branched, asci 8-spored; spores hyaline, straight or curved, non- 

 septate. Spermatia terminal. 



A. Thallus usually yellowish, with sulphury soredia, often broken in the 



center, forming a powdery mass 1. P. ambigua 



A. Thallus grayish white to grayish olive, with concolorous soredia. 



2, P. diffusa 



1. Parmeliopsis ambigua (Wulf.) Nyl. Syn. Lich. 2:54. 1863. 

 Lichen ambiguus Wulf. in Jacq. Coll. Bot. 4:239. 1790. 

 Parmelia ambigua (Wulf.) Ach. Meth. Lich. 207. 1803. 



Thallus naphthalene yellow (R), straw yellow (R), very pale yellow, 

 or grayish white, opaque, stellate, adnate, lobes linear, much branched 

 dichotomously, margins wavy to crenate, tips rounded, smooth near the 

 edge, rough and broken in the center, more or less densely yellow or white 

 sorediate, center is often in the form of an indefinite powdery mass ; below 

 brown to black with scattered black rhizoids. Apothecia rare, 1-4 mm, in 

 diameter; disk pale brown or chestnut brown, concave to flat; thalline 

 margin concolorous with the thallus, crenulate; spores hyaline, usually 

 curved, oblong-ovoid, nonseptate, 6.0-13.0 x 2.5-3.3 /x.. 



On trees, decaying wood, or rock : King-Kittitas Co. : Snoqualmie Pass, 

 3010 ft., 1931, 821. Kittitas Co. : Easton, 2186 ft., 1931, 845. Yakima Co.: 

 Deadhorse Hill, 4500 ft,, 1931, 981a. Ferry Co.: Gibraltar Mt. near Repub- 

 lic, 3100 ft., 1940, 3155. Okanogan Co,: Twisp Trail, 4000 ft., 1931, 1300. 

 Ferry Co.: Laurier, 164 ft., 1931, 1446. Whitman Co.: Tekoa Mountains, 

 2900 ft., 1931, 1600. Columbia Co. : Blue Mountains, 3500 ft., 1931, 1626. 



A small and inconspicuous lichen. The decided yellow color separates it 

 readily from Parmeliopsis diffusa, the only other species found in the state. 



