36 LICHENS OF THE STATE OF WASHINGTON 



hypothecium hyaline or light brown ; paraphyses thick, several septate, tips 

 brownish ; asci 8-spored, hyaline, 3-septate. A monotypic genus. 

 Alga Nostoc. 



1. Hydrothyria venosa Russ. Proc. Essex. Inst. 1 :188. 1853. 



Thallus when dry, brittle, dark brown or black, when moist, rather 

 elastic, light seal brown (R) ; laciniate, lobes irregularly cut, margins 

 deeply incised, veins prominent on the lower surface, also evident on the 

 upper. Apothecia submarginal or subterminal, 0.6-3.0 mm. in diameter, 

 sessile ; disk reddish brown or almost black, flat to convex, the proper mar- 

 gin pale in color, torn-dentate, and disappearing ; spores hyaline, fusiform, 

 3-septate, 26.4-29.7 x 6.6-9.0 fi. 



On rock in mountain streams : Pierce Co. : Mt. Rainier, Berkeley Park, 

 6000 ft., 1931, 612; 1940, 3010; Seattle Park, 4000 ft., 1940, 3060; Van 

 Trump Park, 5000 ft., 1942, 3572. Jefferson Co.: Oueets River Valley, 

 5000 ft., 1907, Frye 15 (W). 



The unusual habitat, in swiftly flowing mountain streams, makes this 

 an easy lichen to recognize in the field. 



15. STICTACEAE 



Thallus foliose, small to very large ; dorsi-ventral ; with definite upper 

 and lower cortices and well-developed algal and medullary layers ; upper 

 surface smooth or reticulate-netted ; below tomentose or villous, interspersed 

 with cyphellae or with naked, light-colored spots ; closely or loosely attached 

 to the substratum by rhizoids. Apothecia marginal or scattered, adnate, 

 sessile, or subpediculate, with either a proper or a thalline margin; asci 

 8-spored; spores brownish, 1 -many-septate. 



Alga Nostoc, Palmella, or Protococcus. 



A. Lower surface of thallus without cyphellae 26. Lobaria 



A. Lower surface of thallus with cyphellae 27. Sticta 



26. Lobaria Schreb. Gen. PI. 2:768. 1789. 



Thallus often large, foliose, broadly expanded, horizontal ; below usually 

 villous or tomentose, cortex interrupted by naked, light-colored, inflated 

 spots, loosely attached to the substratum. Apothecia medium sized, circular, 

 sessile, or subpedicellate, generally with a thalline margin ; hypothecium 

 hyaline or brownish ; paraphyses unbranched, septate ; asci 8-spored ; hya- 

 line or brown, 1-9-septate. 



Alga Protococcus or Nostoc. 



A. Thallus always reticulate-ribbed, below with large white, inflated spots, 

 veins of brown hairs between them. 

 B. Lobes narrow elongated, tips obtuse or retuse-truncate, margins and 



ridges often sorediate or isidiose 2. L. pulmonaria 



B. Lobes broad, often much divided, tips rounded, margins and ridges, 

 undulate-crenate, often fringed with tooth-like lobules. 



1. L. or eg ana 



