154. Parmelia] 39. PARMELIACEAE 327 



the margins cut-crenate; black below and reticulately pitted or finally perforate, 

 without rhizoids; apothecia small to middle-sized, 3-11 mm. across, subsessile, the 

 disk concave to flat or possibly convex, chestnut-brown, the exciple entire to sub- 

 crenate; spores spherical, 3.5—4.5 ^t in diameter. 

 On trees, Washington, Oregon, and California. 



21. Parmelia texana Tuck., Am. Journ. Sci. II. 25:424. 1858. 



Thallus small to middle-sized, adnate, greenish gray, varying toward ashy, 

 becoming reticulately cracked, bearing round, finally confluent soredia, the lobes 

 narrow, becoming long and subdichotomously branched, expanded toward the torn- 

 crenate to lobulate margins; black and papillate below, without rhizoids; apothecia 

 middle-sized, 4-10 mm. across, the disk concave, chestnut-brown, the exciple entire; 

 spores ellipsoid, 11-15 X 4.5-5.5 /a. 



On old wood, Texas (near P. quercina and P. Borreri). 



22. Parmelia sulcata Tayl., in Mack., Fl. Hibern. 2:145. 1856. 



P. saxatilis var. rosaeformis Ach. P. saxatilis var. sulcata (Tayl.) Linds. 



Thallus middle-sized to large, adnate, ashy or less often greenish gray, usually 

 smooth, bearing round to oblong, whitish, finally confluent soredia, the lobes usually 

 broad, oblong to linear, often imbricated, with round, angular, or wavy margins; 

 black below, varying to brown toward the margins, bearing numerous black rhi- 

 zoids; apothecia rare, middle-sized or larger, 4-12 mm. across, sessile to subsessile, 

 the disk concave to deeply concave, chestnut-brown, the exciple entire to crenu- 

 late or irregular; spores short-ellipsoid, 9-15 X 6-9 p. 



On trees and rarely on rocks, throughout northern United States. 



23. Parmelia submarginalis (Michx.) Nyl., Flora 68:607. 1885. 

 Lobaria submarginalis Michx., Flor. Am. Bor. 2:325. 1803. 



Thallus middle-sized to large, greenish gray, adnate, smooth to rough, the 

 lobes broad, becoming crenate and more or less ciliate; black and naked below; 

 apothecia middle-sized to large, 10-20 mm. across, the disk concave, often per- 

 forate, chestnut-brown, the exciple colored like the thallus; spores ovoid-ellipsoid, 

 14-18 X 8-12 fi. 



On trees, the Carolinas, and near New Bedford, Massachusetts. 



24. Parmelia subrugata Nyl., Flora 52:291. 1869. 



Thallus middle-sized to large, adnate, greenish gray varying toward brown, 

 the lobes short and wide to longer and branched, ascending toward the wavy- 

 incised margins, the margins bearing strong, dark rhizoids; black and naked below, 

 pale toward the margins; apothecia middle-sized to large, 4-12 mm. across, sub- 

 pedicellate, the disk deeply concave and becoming perforate at the center, chestnut- 

 brown,- the exciple torn-crenate to lobulate, pitted on the outside; spores 

 oblong-ellipsoid, 30-40 X 18-27 fi. 



On trees, near New Bedford, Massachusetts. It may be but a form of Parmelia 

 perforata (Wulf.) Ach. 



25. Parmelia perforata (Wulf.) Ach., Meth. Lich. 217. 1803. 



Lichen perforatus Wulf., in Jacq., Coll. Bot. 1:116. 1786. P. perforata var. 

 corrugis E. Fries. 



Thallus middle-sized to large, adnate, greenish gray to whitish, frequently 

 wrinkled toward the center, the lobes wide, not much elongated, more or less 

 branched and sometimes imbricated, with round, ciliate, subentire to crenate or 

 irregular margins; brownish black to black below, usually brown toward the mar- 

 gins, and bearing strong, black rhizoids; apothecia middle-sized to very large, 5-24 

 mm. across, subsessile, the disk deeply concave and commonly perforate toward 

 the center, chestnut-brown, the exciple entire to crenate; spores ellipsoid, 9-14 X 

 6-8 /a. 



On trees and rarely on rocks, throughout the United States. 



