132 20. THELOTREMACEAE [72. Phaeotrema 



colored, the proper exciple thin, white, surrounded by a thicker, often disappearing, 

 thalloid one; spores 8, ellipsoid, 3-septate, 1 1-14 X 6-8 /x. 

 On trees, Georgia, Florida, and Louisiana. 



7. Ocellularia carnea (Eckf.) Zahlbr., Cat. Lich. Univ. 2:585. 1924. 



Thelotrema carneum Eckf., Bull. Torr. Club 21:394. 1894. 



Thallus thin, smooth to minutely granulose and warty, rarely somewhat chinky, 

 ashy white to whitish or pinkish white, rarely bordered by and interspersed with a 

 thin black hypothallus; apothecia minute to small, 0.25-0.6 mm. across, immersed, 

 the disk becoming flat, black, slightly rough, the proper exciple thin, black, sur- 

 rounded by a thick, irregular, thalloid one; spores 8, oblong-ellipsoid, 3-septate, 

 11-14 X 3-4 /*. 



On trees, Louisiana. 



72. Phaeotrema Mull. Arg., Mem. Soc. Phys. Hist. Nat. 

 Geneve 29:10. 1887. 



Thallus crustose, smooth to minutely granulose, warty or chinky, rudimentary, 

 commonly devoid of differentiation into layers, attached to the substratum by 

 hyphal rhizoids; apothecia minute to small, more or less immersed, the disk 

 concave to flat, the exciple colored like the disk, thin, sometimes elevated, sur- 

 rounded by a thicker, irregular, thalloid one ; hypothecium and hymenium hyaline : 

 paraphyses unbranched, free or coherent; asci clavate to broadly clavate; spores 

 1-8, brown, oblong to oblong-ellipsoid or fusiform, 3-many-septate. 



The algal host is Trentepohlia. 



1. Phaeotrema californicum (Tuck.) Zahlbr., Cat. Lich. Univ. 2:605. 1924. 



Thelotrema californicum Tuck., Proc. Am. Acad. 12:177. 1877. 



Thallus thin, smooth to warty and sometimes chinky, continuous or irregularly 

 scattered, closely adnate, yellow to straw-colored; apothecia small, 0.3-0.7 mm. 

 across, adnate to sessile, round, the disk flat, black, the exciple colored like the 

 disk, thin, rarely prominent, surrounded by a thicker, entire to flexuous or stellate, 

 thalloid one ; spores 8, ellipsoid to subdactyloid, 3-7-septate, 20-30 X 5-8 fi. 



On trees, San Diego, California. Description made from one by Zahlbruckner 

 based on the cotype in Herbarium of Jean Miiller. 



73. Thelotrema Ach., Meth. Lich. 130. 1803. 



Thallus crustose, smooth to warty, areolate, or chinky, partly within the sub- 

 stratum, commonly devoid of differentiation into layers, attached to the substratum 

 by hyphal rhizoids; apothecia small to middle-sized, immersed to superficial, the 

 disk closed to open, concave to flat, the exciple colored like the disk, thick to 

 thinner, irregular, surrounded by a thin, usually persistent, thalloid one; hypo- 

 thecium hyaline; hymenium hyaline or brownish above; paraphyses unbranched, 

 free; asci clavate to broadly clavate; spores 1-8, hyaline, oblong-ellipsoid, ellipsoid 

 or fusiform, transversely and longitudinally septate, the cells spherical or lenticular. 



The algal host is Trentepohlia. 



A. Spores 1, 128-180 n in length 2. T. interpositum 



A. Spores 1-4 or rarely 8, 4S-140 n in length 1. T. lepadinum 



1. Thelotrema lepadinum Ach., Meth. Lich. 132. 1803. 



Lichen lepadinus Ach., Suec. Prod. 30. 1798. 



Thallus thin to somewhat thick, smooth to rough, chinky, becoming areolate, 

 gray to dull ashy or whitish; apothecia small to middle-sized, 0.4-1 mm. across, 

 slightly immersed to superficial, the disk concave to flat, black or whitish pruinose, 

 the proper exciple thin, brownish black, irregularly torn, surrounded by a thin 

 thalloid one; spores 1-4 or rarely 8, fusiform or oblong-ellipsoid, 11-19-septate 

 transversely and 1-3- or rarely 5-septate longitudinally, 45-140 X 10-25 \i. 



On trees, New England, South Carolina, Florida, Louisiana, California, Oregon, 

 and Washington. 



