20. Clathroporina ] 4. PYRENULACEAE 55 



10. Porina nucula Ach., Syn. Meth. Lich. 112. 1814. 

 Porophora nucula (Ach.) Spreng. 



Thallus thin, becoming warty-granulose, ashy green to gray; perithecia small 

 to middle-sized, 0.3-0.7 mm. across, imbedded in hemispherical or conical thalloid 

 warts, 1 in each, with a small or larger ostiole, the wall dimidiate; spores fusiform- 

 acicular, 7-11-septate, 40-70 X 8-1 1 /x, parallel to irregularly arranged. 



On trees, South Carolina, Florida, Alabama, and Louisiana, 

 var. heterospora Fink; Hedrick, Mycologia 25:308. 1933. 



Spores becoming larger than in species, 5-13-septate, 65-92 X 10-12 fx. 



On trees, Florida. 



11. Porina mastoidea (Ach.) Mull. Arg.; Engler, Bot. Jahr. 6:399. 1885. 

 Pyrenula mastoidea Ach., Ges. Nat. Fr. Bed. Mag. 6:16. pi. 2, f. 16. 1814. 

 Thallus thin to moderately thick, smooth to somewhat rough, greenish gray to 



ashy or sometimes blackening; perithecia minute to small, 0.15-0.45 mm. across, 

 imbedded in thalloid warts, the superficial portion slightly convex, dull black, the 

 ostiole minute, very rarely visible, the wall dimidiate; spores fusiform, sometimes 

 curved, 5- more commonly 7-septate, 32-50 X 5-7 /x, parallel to more commonly 

 irregularly arranged. 

 On trees, Florida. 



12. Porina cestrensis (Tuck.) Mull. Arg., Flora 66:338. 1883. 



Sagedia cestrensis Tuck., Gen. Lich. 265. 1872. Sagedia cestrensis f. olivacea 

 Tuck. 



Thallus thin, smooth to chinky, blackish green, a conspicuous dark hypothallus 

 sometimes present; perithecia minute, 0.1-0.25 mm. across, the superficial portion 

 hemispherical, black, the ostiole invisible, the wall dimidiate; spores fusiform- 

 acicular, larger toward one end, 5-8-septate, 30-115 X 2.5-5 fi, parallel to irregu- 

 larly arranged. 



On trees and rarely on rocks, from New England to Georgia and westward to 

 Alabama and Tennessee. 



var. platyspora Fink; Hedrick, Mycologia 25:308. 1933. 

 Spores 36-50 X 5-9 /x, thus reaching twice the width usually found in the 

 species. 



On beech trunks, near Scipio, Indiana. 



13. Porina rhaphidosperma Mull. Arg., Hedwigia 34:35. 1895. 



Thallus thin, ashy white to grayish, smooth to slightly rough, sometimes be- 

 coming chinky; perithecia minute to small, 0.1-0.35 mm. across, sometimes clus- 

 tered, the superficial portion hemispherical, dull black, the ostiole minute, rarely 

 visible, the wall dimidiate; spores acicular, 7-11-septate, 60-70 X 1.5-2.5 /a, parallel 

 to irregularly arranged. 



On trees, southeastern United States. 



OTHER SPECIES REPORTED 



Porina faginea (Schaer.) Arnold. — Massachusetts and Illinois. 



20. Clathroporina Mull. Arg., Flora 65:517. 1882. 



Thallus forming a very thin to thin, smooth crust over the substratum, partly 

 or wholly within the substratum, devoid of differentiation into layers; perithecia 

 minute to small, more or less immersed, the superficial portion convex or subcorneal, 

 the wall dimidiate, the ostiole minute, punctiform; paraphyses unbranched; asci 

 clavate; spores 8, hyaline, ellipsoid to oblong or fusiform, transversely and longi- 

 tudinally septate, the cells cylindrical. 



The algal host is Trentepohlia. 



