130 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
physes coherent, their tips clavate and colored, septate, a few furcate below the 
heads; hypothecium colorless; asci inflated-clavate; spores 8, bluntly ovoid-ellipsoid, 
16 to 22 » long, 7.5 to 9 « thick, brown, bilocular, toward maturity slightly constricted ; 
hymenial gelatine with iodine blue. 
On barks chiefly, but also on rocks; rarely found in fruit. Throughout the United 
States; also in Europe and in Algeria. 
7. Physcia setosa (Ach.) Nyl. 
Thallus loosely appressed, gray and grayish brown, laciniate, the lacinie sinuate 
and lobed and cushioned upon a bed of short black fibrils, no reaction with potassium 
hydrate or calcium chloride; apothecia few, sessile, small, not over 1.25 mm. wide; 
disk concave, brown black; thalline margin incurved, turgid, entire, the amphithe- 
cium also with the characteristic fibrils; “spores 20 to 25 4 long, 10 to 14 » thick.”’ 
(Tuckerman. ) 
On earth (apparently); collected by T. 8. Brandegee in Lower California. 
8. Physcia tribacia (Ach.) Nyl. 
Lobes short, dilated, imbricate, suberect, lacerate-crenate and leprose-sorediate at 
the border, KHO+ yellow, Ca(ClO),—, beneath white with fine fibrille; only sterile 
plants found. 
Upon earth and rocks in the Santa Monica and San Gabriel Ranges. 
9. Physcia pulverulenta (Schreb.) Ny. 
Thallus orbicular, loosely appressed, pale greenish to reddish brown, manifold- 
laciniate, the lacinix separate from the center, much cleft and spreading toward the 
periphery, hence contiguous and imbricate, the termination lobulate-crenate, prui- 
nate especially toward the paling extremities of the laciniw, KHO—, beneath dark, 
paling outward, dark-fibrillose; apothecia sessile and subpedicellate, often crowded 
centrally, 0.5 to 2.5 mm. wide; disk concave to flat, densely pruinose; thalline margin 
persistent, erect (containing but few gonidia, none beneath the hypothecium), at 
times with several ray-like lobules; epithecium dark reddish brown, gradually fading 
downward, imposed upon it a thin hyaline layer (pruina?); thecium 140 to 144 »: high, 
faintly brownish, the lower part nearly colorless; paraphyses coherent, indistinctly 
septate, slightly clavate above, some furcate below the tips; hypothecium faint brown; 
asci clavate, reaching the lower border of the colored epithecium, the membrane 
thickened above; spores 8, ovoid, broadly ellipsoid, 24 to 32 long, 12 to 16 »# thick, 
bilocular, dark brown, constricted, the lumina large, round; all the hymenial 
structures stained blue with iodine, except the hyalline layer above the epithecium. 
On barks and rock, throughout from the foothills and extending to higher eleva- 
tions, where (above 1,000 meters) it attains its best development. Of its varying 
forms the following are found in our territory: Forma leucoleiptes Tuck., white with 
the “‘lobes flat, interruptedly elevated and powdery at the margins, beneath black’’— 
on Sambucus glauca in the Santa Monica Range; forma muscigena (Ach.) Nyl., having 
the lacinie short and broad, imbricate, gray to mostly chestnut brown, very seldom 
found in fruit—on earth and rocks; and forma argyphaea Ny1., with the lacinix broader 
and shorter than in the species of the other forms, the distinguishing character, how- 
ever, being the dense, white pruina covering disk and thallus—more common than 
the preceding forms but often sterile; on the ground and on rocks in the San Gabriel 
Range; on bark of Fraxinus dipetala, Topanga Canyon, Santa Monica Range. 
9a. Physcia pulverulenta angustata Ny]. 
Thallus in color like the species, but somewhat paler, the lacinixe narrow, resting 
on dense cushions of dark fibrils. 
On smooth oak bark along the “New Trail” to Wilson’s Peak on the western slope 
of the San Gabriel Range at about 800 meters. 
