336 39. PARMELIACEAE [155. Cetraria 



5. Cetraria lacunosa Ach., Meth. Lich. 295. pi. 5, f. 3. 1803. 



Platysma lacunosum f. atlanticum (Tuck.) Nyl. C. lacunosa f. cavernosa 

 (Menz.) Merrill. 



Thallus foliose, middle-sized to large, greenish gray to straw-colored, the lobes 

 crowded, wide, reticulately pitted, the margins ascending, torn-crenate; brownish 

 to black below; apothecia middle-sized to large, 1-10 mm. across, numerous, sessile 

 to subpedicellate, marginal to subterminal, frequently perforate in the center, the 

 disk concave, chestnut-brown, the exciple thin, entire, sometimes disappearing; 

 spores short-ellipsoid, 5-8 X 4-5 //,. (Plate 36 b.) 



On trees, throughout northern United States, and southward in the mountains. 



6. Cetraria aurescens Tuck., Proc. Am. Acad. 1:208. 1848. 



Thallus small to middle-sized, foliose, straw-colored to greenish gray, the lobes 

 narrow, many-cleft, the margins ascending, laciniate, curled; pale below, with fre- 

 quent pale to brownish rhizoids ; apothecia middle-sized to large, 1-7 mm. across, 

 marginal, subpedicellate, the disk concave to irregular, chestnut-brown, the exciple 

 crenulate; spores subspherical to ellipsoid, 3-6 X 3-5 /x. 



On conifers and old rails, from New England to Alabama, and westward to 

 South Dakota and Minnesota. 



7. Cetraria stenophylla (Tuck.) Merrill, Bryologist 13:27. 1910. 



C. lacunosa var. stenophylla Tuck., Syn. N. A. Lich. 1:35. 1882. 



Thallus foliose, middle-sized to large, greenish gray to straw-colored or brown- 

 ish, much lobed, the lobes narrow, elongated, crowded, somewhat channeled, the 

 margins ascending, irregularly torn-crenate; whitish to straw-colored or darker 

 below; apothecia middle-sized to large, 1-10 mm. across, terminal, sessile to sub- 

 pedicellate, the disk concave, irregular, chestnut-brown, the exciple thin, entire, 

 sometimes disappearing; spores short-ellipsoid, 5-7 X 3.5-5 /a. 



On trees, throughout northern United States, and in California. 



8. Cetraria Fendleri (Nyl.) Tuck., Gen. Lich. 280. 1872. 

 Parmelia Fendleri Nyl., Syn. Meth. Lich. 1:309. 1860. 



Thallus scanty to small, foliose, smooth, irregularly many-cleft, pale to brown- 

 ish olive-green, the lobes irregular, very narrow, branched, becoming crowded and 

 complicate, the margins toothed; pale and rough below with scattered pale rhi- 

 zoids; apothecia numerous, small, 1-4 mm. across, marginal, the disk concave to 

 convex, becoming irregular, chestnut-brown, usually shining, the exciple crenulate; 

 spores subspherical to ellipsoid, 4.5-11 X 3.5-5 ju.. 



On trees and wood, from Massachusetts to Alabama, and westward to New 

 Mexico and Colorado. 



9. Cetraria saepincola (Ehrh.) Ach., Meth. Lich. 297. 1803. 

 Lichen saepincola Ehrh., Hanover Mag. 206. 1783. 



Thallus small, foliose, pale to darker chestnut-brown, or olive-green, the lobes 

 few and short, prostrate to ascending, smooth to somewhat wrinkled, the margins 

 undulate and crenate; pale below without rhizoids; apothecia small, 0.7-4.5 mm. 

 across, marginal, sessile, the disk concave to convex, of the same color as thallus 

 to darker, the exciple entire to crenulate; spores ellipsoid, 6-9.5 X 3-6 p.. 



On trees, from New England westward to Oregon and California. 



10. Cetraria chlorophylla (Willd.) Vainio, Lich. Caucas. Term. Fiiz. 22:278. 



1899. 

 Lichen chlorophyllus Willd., in Humb., Fl. Friberg 20. 1793. C. saepincola var. 



chlorophylla (Willd.) Schaer. 

 Thallus small to scarcely middle-sized, pale to darker chestnut-brown or olive- 

 green, the lobes numerous, short, irregular, prostrate or ascending, the margins 



