57. Helminthocarpon 16. CHIODECTONACEAE 119 



to curved or flexuous, infrequently branched, the disk open, flat, more or less 

 grayish pruinose, or finally black, the proper exciple brown, surrounded laterally 

 by a rarely disappearing thalloid one; hypothecium hyaline; spores 8, or rarely 4, 

 oblong-ellipsoid, 11-17-septate transversely and 2-5-septate longitudinally, 50-85 

 X 14-25 /a. 



On trees, Florida and Louisiana. 



4. Phaeographina Columbiana (Tuck.) Zahlbr., Cat. Lich. Univ. 2:436. 1924. 

 Graphis Columbiana Tuck., Syn. N. A. Lich. 2:123. 1888. 



Thallus thin, smooth, pale greenish gray to ashy; apothecia short and narrow, 

 0.5-3.5 X 0.2-0.25 mm., immersed, straight to curved or obscurely flexuous, close- 

 ly grouped and often branched, the disk closed to finally open and brown, the 

 proper exciple thin, brown to reddish brown, surrounded laterally by a thalloid 

 one; hypothecium hyaline; spores 8, oblong-ellipsoid, 3-7-septate transversely and 

 1-3-septate longitudinally, 14-30 X 8-12 fi. 



On trees, Florida and southern Alabama. 



5. Phaeographina explicans Fink; Hedrick, Mycologia 25:313. 1933. 



Graphis dendritica var. explicans Tuck, in litt. 



Thallus thin, smooth, greenish yellow to olive-green; apothecia moderately long 

 and wide, 1-3 X 0.2-0.4 mm., partly immersed to adnate, straight to much more 

 commonly curved or flexuous, rarely branched, but more often clustered, some- 

 times radiately, the disk open and flat, blackish brown or obscurely grayish pru- 

 inose, the proper exciple dark brown; hypothecium brown; spores 8, oblong-ellip- 

 soid, 3-7-septate transversely and 1-septate longitudinally, 21-35 X 8-12 fi. 



On trees, Alabama. 



57. Helminthocarpon Fee, Essai Crypt. Suppl. 156. 1837. 



Thallus crustose, whitish, usually smooth; apothecia becoming adnate, covered 

 partly or wholly by the thalloid exciple, round to elongated, exciple thin and dark- 

 colored; hypothecium hyaline; paraphyses much branched and interwoven, the 

 apex not thickened; asci oblong or clavate; spores 4-8, hyaline, transversely and 

 longitudinally septate. 



The algal host is Trentepohlia. 



1. Helminthocarpon Leeprevostii Fee, Essai Crypt. Suppl. 156. pi. 35, f. 11. 

 1837. 



Thallus moderately thick, smooth to minutely warty, pale greenish gray to 

 whitish; apothecia middle-sized, 0.5-1 mm. across, or reaching 3 mm. in one direc- 

 tion, adnate, round to irregular or elongated, straight to rarely curved or flexuous, 

 rarely branched, the disk flat, white, the exciple thin and dark brown, covered 

 laterally and sometimes above by a thick thalloid one; spores 4-8, oblong-ellip- 

 soid, 13-35-septate transversely and 4-7-septate longitudinally, 110-165 X 22-50 /x. 



On trees, Louisiana. 



16. CHIODECTONACEAE 



Thallus crustose, partly within the substratum, showing little or no differen- 

 tiation into layers, attached to the substratum by hyphal rhizoids; apothecia more 

 or less immersed in a stroma, round to elongated, sometimes branched, the proper 

 exciple usually well developed; paraphyses unbranched and free or branched and 

 more or less interwoven. 



The algal hosts are Trentepohlia and Phycopeltis. 



A. Paraphyses unbranched and free 



B. Spores transversely septate 



C. Spores hyaline 58. Glyphis 



C. Spores brown 59. Sarcographa 



B. Spores transversely and longitudinally septate 60. Medusuldja 



