102 15. GRAPHIDACEAE [51. Opegraphoidea 



22. Opegrapha prosodea Ach., Meth. Lich. 22. 1803. 



Thallus thin and smooth to thicker and sometimes obscurely rough, pale or 

 darker greenish gray or tinged with brown, usually limited by a blackish line; 

 apothecium often somewhat elongated but remaining narrow or of moderate width, 

 0.8-5 X 0.2-0.5 mm., with obtuse or somewhat pointed ends, partly immersed to 

 adnate, commonly scattered, straight to more commonly curved or obscurely flex- 

 uous, infrequently branched, and rarely stellately so, the disk closed to rarely 

 open, flat and dull black, the exciple black and moderately thick; hypothecium 

 brownish black; spores oblong-fusiform, 5-15-septate, 24-32 X 6-11 /x. 



On trees, Florida, Louisiana, Minnesota, and Texas. 



23. Opegrapha Bonplandi Fee, Essai Crypt. 25. pi. 5, f. 4. 1824. 



Thallus very thin to thin, smooth to slightly rough, pale greenish gray to ashy 

 or brownish, often limited by a dark brown to black line, frequently disappearing; 

 apothecia of medium length and width, 0.5-4 X 0.2-0.4 mm., oblong to linear- 

 oblong or more nearly ellipsoid, adnate, usually scattered, straight to curved or 

 rarely and obscurely flexuous, very rarely branched, the disk closed to more or 

 less open, flat to concave, dull black, the exciple black; hypothecium brownish 

 black; spores narrowly fusiform, 5-11-septate, 20-42 X 3.5-7.5 fi. 



On trees, Florida, Louisiana, and Texas. 



24. Opegrapha viridis Pers., in Ach., Meth. Lich. 22. 1803. 



Thallus thin, smooth to scurfy, dark grayish green to yellowish or brownish; 

 apothecia short to somewhat elongated but rather narrow, sometimes tending 

 toward round or irregular forms, 0.3-1.5 X 0.13-0.2 mm., the ends obtuse, slightly 

 immersed to adnate, scattered or clustered, straight to curved, rarely branched, 

 the disk closed to rarely and narrowly open, flat, and black; hypothecium brownish 

 black; spores fusiform-acicular, 7-15-septate, 35-70 X 4.5-7.5 /x. 



On trees, Massachusetts, Illinois, Florida, and Missouri, the northern speci- 

 mens doubtful. 



OTHER SPECIES REPORTED 



Opegrapha levidensis Willey — Massachusetts. 



Opegrapha mesophlaebia Nyl. — Louisiana. 



Opegrapha oulocheila Tuck. — North Carolina. 



Opegrapha scaphella var. gemella (Eschw.) Eckf. — North Carolina. 



51. Opegraphoidea Fink; Hedrick, Mycologia 25:311. 1933. 



Thallus immersed in that of the lichen host and therefore invisible; apothecia 

 round to more commonly oblong, partly immersed to adnate, scattered to clustered, 

 the disk closed to rarely open, the exciple usually black; hypothecium commonly 

 brownish black; paraphyses branched and interwoven; asci clavate to broadly 

 clavate; spores 4, usually 8, hyaline to brownish or rarely brown, oblong to 

 oblong-ellipsoid or ellipsoid-pointed, 3-septate, the cells cylindrical. 



The algal host is usually Protococcus or that of the lichen host. 



A. Apothecia conglomerate 



B. Spores 4, hyaline to brownish 1. O. quaternella 



B. Spores reaching 8, brown 2. O. pulvinata 



A. Apothecia scattered or clustered 3. O. staurothelicola 



1. Opegraphoidea quaternella (Nyl.) Fink n. comb. 



Opegrapha quaternella Nyl., Flora 68:449. 1885. 



Thallus within the substratum and invisible; apothecia minute, irregular to 

 oblong and straight, 0.25-0.6 X 0.18-0.3, partly immersed to adnate, conglom- 

 erate in areas 2-3 mm. across with several to many in each area, the disk closed, 



