HERRE THE GYROPHORACEAE OF CALIFORNIA. 321 



crowds out all other forms but one, Acarospora thamnina, though it is doubtful if any- 

 other lichens besides these two could exist on such dry, hot rocks as they monopolize. 



In addition to numerous localities in the Santa Cruz Peninsula I have examined 

 material from other Calif ornian localities as follows: Inner Coast Range, Mount Hamil- 

 ton and Mount Santa Ana; Tuscan Butte, Shasta County; Napa Valley, /. Torrey, 

 1865; Marin County, Bolander; Klamath, Siskiyou County; Hood's Peak, Sonoma 

 County; Sims, Shasta County; Mount Diablo; Tehachepi Mountains, Doctor Hasse; 

 Vallecito, Lower California; Moreno, Cummings, Williams & Seymour, Dec. N.Amer. 

 Lich. no. 157. 



This lichen seems to reach a greater thalline development in the dry inner Coast 

 Range than elsewhere. A specimen in the Tuckerman Herbarium from Mount Diablo 

 has a diameter of 7.5 cm., while I have collected specimens on Mount Santa Ana with 

 a breadth of 10 cm. 



This species ranges from Vancouver Island on the north to Guadalupe Island, off 

 Lower California, a specimen from the latter locality being in the Tuckerman Her- 

 barium, and from the western part of Nevada to the Pacific. 



Explanation of Plate. 72. — a,b,c, Upper surface of thallus; d, under surface of plant shown in a. 

 Specimens from Mount Santa Aria.. All scale 2. 



2. UMBILICARIA (Hoffm.) Flot. 



Umbilicaria Hoffm. Descr. PL Crypt. 1: 7. pi. 2.f. 1-4. 1790. 



Thallus attached by a central or nearly central umbilicus, without rhiztiida. 

 Apothecia usually simple, with smooth disk, in some forms becoming elevated, 

 plicate, and proliferous. Spores rarely more than 1 or 2 in the asci, brown, though 

 often a long time colorless, muriform-multilocular. 



The type Bpecies is presumably Umbilicaria pustulata (L.) Hoffm. (PL 73) . Species 

 about a half dozen in number, mostly of the temperate zone. 



Explanation of Plate 73.— a, Under surface showing pitted formation; 6, upper surface. Both natural 

 size. 



1. Umbilicaria semitensis Tuck. Gen. Lich. 41. 1872. 



Umbilicaria angulata semitensis Tuck. Syn. N. Amer. Lich. 1: 88. 1882. 



Thallus small to medium (3 to 5 cm. in diameter, Hasse), one-leaved or sometimes 

 several-leaved, rigid, often undulate; upper surface varying from smooth or even 

 polished to finely areolate or sometimes granulose, in color smoky gray, gray brown, 

 and dark brown or chocolate; under surface black or gray black, coarsely granular; 

 radiately ridged, the ridges becoming lacerate and passing into scattered fibrils; 

 apothecia small to medium, innate or appressed, usually crowded toward the circum- 

 ference, and often confluent, angular, circular, or irregular, plicate, black, with a 

 thick persistent margin; paraphyses slender, free or more often confluent, hardly 

 longer than the clavate or ventricose asci; thecium blue, finally red brown with iodine; 

 spores in Yosemite specimens solitary or in couples, muriform, usually colorless, but 



at last brown, 19 _ 2 3% ^ e P ecimena from the Tehachepi Range yield spores ^-^ ft. 

 In specimens collected by Bolander in 1868, locality unknown, there are, as a rule, 



. , j 15-20.5 



one or two spores in the asci, but they also occur mas. and measure 26-30 P- 



This plant has been collected at Yosemite Valley by Bolander, Prof. Clara Cum- 

 mings, and Doctor Hasse; the latter has also found it in the Tehachepi Range and in 

 the Santa Monica Range. As yet it is not known to occur outside California or north 

 of the latitude of the San Francisco Bay region. Cummings, Williams, & Seymour, 

 Dec. N. Amer. Lich. no. 148, Yosemite Valley, California. 

 70272°— vol 13, pt 10—11 2 



