84 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
spores fusiform, acicular, 68 » long, 4 thick, 5 or 6-locular; with iodine the asci 
staining blue, the rest of the hymenial structures orange red. 
On earth; San Bernardino Mountains, Parish; Matilija Canyon, Ventura County; 
Yosemite Valley. Northern Atlantic Coast; Europe; Tasmania; New Zealand. 
PERTUSARIACEAE. 
The genus Pertusaria is the sole representative of this family with us. 
PERTUSARIA Lam. & DC. 
Thallus crustaceous, uniform, intimately affixed to the substratum by medullary or 
hypothalline hyphe, the gonidial layer, covering the medullary, composed of Cystococ- 
cus gonidia (synonyms Pleurococcus, Protococcus); apothecia either lecanoroid with a 
thalline margin, or the hymenia immersed in thalline verruce, one to several in each, 
the disk then contracted, punctiform or seen as a mere depression of the thalline wart; 
paraphyses branching, slender; asci containing 1 to 8 spores, these simple, colorless, 
generally very large, the epispore thick; spermogones immersed in the Verruce ; 
spermatia cylindric to acicular. 
KEY TO SPECIES. 
Growing on rock. 
Thallus sulphur-colored, rimose..............2.2.2.2.2.0.00- 2. P. flavicunda. 
Thallus whitish gray, smooth.....................0.eee0eeeeee 3. P. nolens. 
Growing on bark. 
Thallus whitish to light gray. 
Disk pruinose, flesh-colored..................0..0.0.0002- 1. P. lecanina. 
Disk not pruinose, dark, small............. wee eee eeeeee 6. P. leioplaca. 
Thallus dark ash gray. 
Disk dilated, round, black...............2..2..2-22----.. 4. P. wulfenii. 
Disk punctiform, stellate or irregular-shaped............. 5. P. pustulata. 
1. Pertusaria lecanina Tuck. 
Thallus smooth, becoming slightly rugulose, creamy yellow, with a dark hypo- 
thalline border; apothecia sessile, from 0.5 to 1.25 mm. in width; disk with a thalline 
margin, primarily flat, thickly pruinose, at last slightly depressed and pale rose color, 
KHO staining the thalline margin of the mature apothecia orange, then red, the thal- 
lus faint yellowish; this stain of the thalline margin appearing on the species only when 
growing upon Juglans californica; epithecium colorless; thecium colorless; para- 
physes free, slender, forked; hypothecium colorless; asci thick-walled, 2-spored ; spores 
112 to 140 u long, 40 to 48 » thick, the epispore very thick; hymenial gelatine with 
iodine a deep blue. 
On the smooth barks of the wild walnut, and of Quercus agrifolia; less common on 
other barks. Frequent in the Santa Monica Range. According to Tuckerman it 
occurs in small patches accompanying Pertusaria leioplaca and P. communis; in South- 
ern California the patches are often large and without the association of these two 
species. 
2. Pertusaria flavicunda Tuck. 
Thallus sulphur-colored, rimose-areolate, the areoles angular, granular or minutely 
verruculose, diminishing in size toward the circumference or becoming indistinctly 
radiate; hypothallus pallid, KHO-+-yellow, Ca(ClO),-++orange; apothecia sessile, ver- 
rucose; disk flat, somewhat impressed, dark dusky yellowish pruinose, round or angu- 
lar, in places the apothecia supplanted by isidiose glomerules; spores 2 or 3, 
ovoid-ellipsoid, 80 to 84 » long, 46 to 52 « thick, the epispore very thick; hymenial 
gelatine deep blue with iodine, the spores yellow. 
On rocks and siliceous pebbles at San Diego; at Del Mar; calcareous rocks near 
Santa Monica; Santa Catalina Island. Appears to favor localities not distant from 
the ocean. 
