390 PROCEEDINGS OF THE AMERICAN ACADEMY 



Vai-. ^. riTYREA, Fr., thalli (magis cinereo-virentis) laciniis adscen- 

 dentibus subtus fibrillosis margine pulverulentis. Fr. 1. c. & Licli. 

 Suec. n. 105. Lichen, dein Parmelia pityrea, Ach. ; Moug. & Nestl. 

 Cr. Vog. n. 352. P. pulverulenta, y.grisea, Schtcr. Spicil. p. 446, & 

 Lich. Helv. n. 487. Lichen leucoleiptes, Muhl. in Herb. Willd. P. 

 pulverulenta, v. leucoleiptes, Tuckerm. Synops. Lich. N. E. p. 32, & 

 Lich. Exs. n. 107. On rocks and trees. Pennsylvania, Muhlenherg. 

 New England to Virginia, common. Texas, Mr. Wright. Mountains 

 of New Mexico, Mr. Fendler. Lobes often wider than those of a, and 

 rock-specimens of the present contrast strongly with tree-specimens of 

 the former. The present is analogous to, and often much resembles 

 P. speciosa /3. (^Parm. granulifera, Ach., in the state with the margins 

 of the lobes raised and powdery), but the two Lichens are distinguish- 

 able, and appear to represent different types ; this presenting the 

 strongly black-fibrillose underside of P. pulverulenta. 



9. P. SPECIOSA (Wulf., Fr.) : thallo cartilagineo-membranaceo vire- 

 scenti-glauco subtus molliusculo e lacteo fuscescente ; laciniis obtusis 

 multifidis subciliatis ; apotheciis subpodicellatis disco rufo-fusco nigri- 

 cante margine thallino incurvo mox crenato-fimbriato. SporjE octonje, 

 majuscula3, fuscescentes, ellipsoideoe, uniseptatte, diam. 2-3-plo longioris. 



Var. a. STELLATA : laciniis appressis subelongatis inciso-ramosis pin- 

 natifidis margine adscendentibus epruinosis subtus nisi apice epulveru- 

 lentis ; apotheciis subsessilibus mox nudis. Lichen speciosus, Wulf. in 

 Jacq. Coll. IIL p. 119, t. 7. Parmelia, Ach. Lichenogr. p. 480 ; Syn. p. 

 211 ; Fr. Lichenogr. p. 80, a; Moug. & Nestl. Cr. Vog. n. 635 ; Schier. 

 Spicil. p. 447, & Lich. Helv. n. 357 ; Tuckerm. Synops. Lich. N. E. 

 p. 33, & Lich. Exs. n. 81 ; Nyl. Prodr. Gall. 1. c. p. 61. On trunks 

 and mossy rocks in woods. Pennsylvania, Muhlenherg, 1796 (Hoffm. 

 D. Fl. IL 153). New England to Virginia, common in the mountains, 

 but somewhat rarely fertile ; the ascendent margins of the lobes often 

 powdery, or passing, on rocks, at the centre, into a thick powdery crust. 

 Lake Superior, Prof. Agassiz. Wisconsin, 3Ir. Lapham. North Car- 

 olina, infertile. Rev. Dr. Curtis. South Carolina, in the upper country, 

 infertile, Mr. Ravcnel. Alabama, infertile, Mr. Beaumont. Louisiana, 

 Dr. Hale. 



Var. /3. GRANULiFEKA : stellata, appressa ; laciniis subplanis irregu- 

 lariter laciniatis dentato-crenatis (subpruinosis) granulis globosis niveis 

 aspersis margine demum adscendentibus subtus glabris e fusco nigri- 



