LICHENS OF SANTA CRUZ PENINSULA 359 



Lichen conspcrsus Ehrh. in Ach. Prodr. ii8. 1798. 

 ParmeUa conspcrsa h.z\\. Meth. Lich. 205. 1803; Lich. Univ. 

 486. 1810. 



VIII. Physcia (DC.) Th. Fr. 



Thallus usually foliaceous, stellate or orbicular, appressed, 

 laciniately branched or lobed ; more rarely fruticose or ascen- 

 dant ; beneath fibrillose or more seldom naked. Apothecia 

 usually abundant, shield-shaped; the disk dark or blackish, 

 often pruinose ; spores bilocular, ellipsoid, brown. 



This widely distributed genus is well represented in our terri- 

 tory, one or more species being present everywhere from sea 

 level to the summit of the range. 

 Physcia Th. Fr. Lich. Arctoi 60. i860. 



KEY TO THE SPECIES. 



a. Thallus fruticose, sterile, fringed with long black fibrils; on earth. 



2. leucomela^ 360. 

 aa. Thallus foliaceous. 



b. Thallus not appressed, lobes ascendant or sub-fruticose. 



c. Apothecia abundant; plant fuzzy, with long fibrils; maritime 



trees and shrubs i. erinacea^ 360. 



cc. Sterile ; tips of ascendant lobes vaulted or hood-like. 



1 1 . Jiispida^ 364. 

 bb. Thallus appressed. 



d. Surface not pruinose. 



e. Color usually brown; thallus very thin, closely adherent, 

 seemingly apart of the substratum. .12. adgluti^iata^ 365. 

 ee. Color white or glaucous. 

 f. Thallus sorediate; margin of lobes upturned, much cut. 



10. tribacia^ 364. 

 ff. Thallus not sorediate; thickly sprinkled with small, 

 white, sub-epidermal spots. 

 g. Under surface white, with white fibrils. 



8. stellar is,, 3^3' 

 gg. Under surface black with black hispid fibrils. 



9. aipolia^ 3^3' 

 dd, Thallus more or less pruinose. 



h. Medullary layer and soredia more or less yellow or sulphur- 

 color 7. muscigena^ 3^3. 



hh. Medullary layer white or greenish white. 



i. Apothecia with leafy or lobulate margin. .6. venusta^ 2^62. 



