38S PROCEEDINGS OF THE AMERICAN ACADEMY 



Var. STELLATA, Nyl. : thallo orbicular! stellato viridi-flavo ; laciniis 

 planis ambitu multifidis demum subconnatis ; apotheciis saturate flavis 

 rufescentibus margine thallino integro demum plicato subtus radiato- 

 fibrillosis. Sporfe minutre, ellipsoideaj, incolores, " polari-dyblastge," 

 plures (c. 20) in tliecis. P. candelaria, v. stellata, Nyl. Enum. Gen. 1. c. 

 p. 106. Parmelia diversicolor, Ach. Syn. p. 210, pro p. P. {Physcia) 

 jilrosa, Fr. PI. Homon. p. 284 ; Lichenogr. p. 75. P. jihrosa j3. stel- 

 lata, Tuckerm. in Darlingt. Fl. Cestr. p. 440, & Lich. Exs. n. 88. 

 On trees and rocks. Pennsylvania, MuJilenherg, 1796 (e Hoffm. D. 

 Fl. 2, p. 159). New England, common. New York, Dr. Sartwell. 

 Ohio, Dr. Hayden. North Carolina, Dr. Curtis. South Carolina, 

 Mr. Ravenel. Alabama, Mr. Peters. Louisiana, Dr. Hale. Texas, 

 3Ir. Wright. The relation of this Lichen to Physcia was pointed out 

 by Fries, 1. c. ; but its full determination, as a stellate, foliaceous form 

 of the European Parmelia candelaria, a, of Acharius, was left for the 

 microscope, in the able hands of Dr. Nylander. The presence of 

 fibres on the under side of the thalline exciple is a far less uncommon 

 feature in American Lichens than it is in European. 



§ II. Species thallo glauco-fuscescente ; sporis hyalinis uniseptatis. 



4. P. EUPLOCA, Tuckerm. : thallo suborbiculari moUiusculo fragili 

 glabro e laciniis tereti-compressis dichotomo-ramosissimis apice furcatis 

 implexis appressis glauco-fuscescentibus subtus albidis nudis ; apotheciis 

 sessilibus disco fuscescente demum convexo marginemque crassiusculum 

 subcrenulatum excludente. Spora3 suboctona; in thecis, parvulte, ob- 

 longoe, incolores, uniseptatte, diam. 3 - 3^-plo longiores. Tuckerm. 

 Suppl. in Amer. Journ. Sci. 25, p. 424. Rocks on the banks of creeks 

 in the hills of the Blanco, Texas, Mr. Wright. An elegant species 

 without near affinity, that I can trace, to any other. 



§ III. Species thallo glaucescente (fuscescente) ; sporis fuscescentihus 



uniseptatis. 



5. P. ERiNACEA, Ach. Lichenogr. p. 599 ; Syn. p. 222. On trees, 

 California, Menzies. Sea-coast of California, Dr. Parry (Herb. Torr.). 

 The entire thalline margin of the apothecia appears to distinguish this 

 Lichen, which, in the thallus, resembles the next species, and also some 

 forms of P. speciosa. 



6. P. ciLiARis (L.) DC. var. angustata, Tuckex'm. Synops. p. 32. 



