110 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
1. Evernia prunastri (L.) Ach. 
Thallus soft, pliant, compressed, pale whitish green above, beneath white-channeled 
longitudinally, divaricately branching, the ultimate divisions linear or often forked 
at the ends; fruiting specimens thus far not found. 
The margins of the lacinie are more or less sorediiferous, and when the soredia are 
continuous it is the forma sorediifera Ach., though its limitation seems a matter of 
opinion. 
Quite common in our district on shrubs and trees, on the mainland as on the islands 
of the archipelago. 
LETHARIA (T. Fries) Zahlbr. 
Thallus citrine yellow, flattened-terete, fruticulose, branching; medulla loose- 
webby, irregularly traversed by strengthening cords, 
A single species with us. 
1. Letharia vulpina (L.) Wain. 
Fruticulose, erect, about a span high, though oftener not attaining that height, 
yellow or greenish yellow, terete or subcompressed, lacunose and furrowed; apothecia 
terminal and subterminal; disk concave to flat, red brown to blackish brown, from 
0.5 to 2 or even 3.5 cm. in diameter, the frequently radiately fibrillose thalline margin 
finally obsolete; spores ovoid-ellipsoid, 5 to 8 « long, 4.5 to 5 # thick. 
With us mostly on conifers, living or dead, rare below 1,500 meters. Mountains of 
Lower California, Greene. Pacific coast and the Rocky Mountains; Europe. 
CALOPLACACEAE. 
Thallus crustaceous, uniform or lobed at the periphery, or reduced-fruticulose; 
gonidia Protococcus; apothecia circular, innate or sessile, lecanorine or biatorine; 
spores colorless, polari-bilocular, seldom quadrilocular or simple; sterigma jointed; 
spermatia short, straight, oblong or ellipsoid. 
KEY TO GENERA. 
Apothecia biatorine or lecideine; margin without gonidia.. BLasTenta (p. 110). 
Apothecia lecanorine...............-.......-.- Lee eeeeee CALOPLACA (p. 112), 
BLASTENIA Mass. 
Thallus crustaceous, uniform, pulverulent or rimose; apothecia innate or sessile, 
with a proper margin; asci 4 to 16-spored; spores colorless, ellipsoid or oblong, polari- 
bilocular, rarely quadrilocular or simple; sterigma short, straight, rarely acicular or 
bowed. 
KEY TO SPECIES. 
Substratum bark. 
Thallus gray, chinky............2.2.0....-.......... 1. B. ferruginea. 
Thallus whitish, granulose........................... 1b. B. ferruginea wrightit. 
Substratum mineral. 
Substratum earth. 
Apothecia rusty orange, small................... 4. B. subpyraceella. 
Apothecia bright orange to vermilion ............ 3. B. luteominia. 
Substratum rock. 
Thallus obsolescent or absent. ................... 2. B. festiva. 
Thallus present. 
Ochraceous, poorly developed. 
Apothecia bright vermilion............. la. B. ferruginea bolanderi. 
Apothecia rusty orange..............-.. 4. B. subpyraceella. 
Whitish, pulverulent........................ le. B. ferruginea fraudans. 
