69. Schismatomma ] 19. LECANACTIDACEAE 129 



3. Schismatomma pericleum (Ach.) Branth & Rostr., Bot. Tidss. 3:244. pi. 4, f. 



51. 1869. 



Lichen pendens Ach., Lich. Suec. Prod. 78. 1798. Platygrapha periclea (Ach.) 

 Nyl. S. dolosum (E. Fries) Flotow. 



Thallus thin, composed of minute, whitish, scurfy granules, contiguous and 

 finally forming a chinky crust; apothecia minute to small, 0.15-0.4 mm. across, 

 round or oblong and rarely sparingly branched, the disk flat to convex, dark brown 

 to black, the exciple thick, white, rarely disappearing, covering a very thin, incon- 

 spicuous, proper one; hypothecium dark brown; spores bluntly acicular, 3-septate. 

 30-38 X 2.5-4 /*. 



On trees, New Hampshire, Massachusetts, and Tennessee. 



4. Schismatomma Ravenelii (Tuck.) Zahlbr., Cat. Lich. Univ. 2:564. 1924. 

 Platygrapha Ravenelii Tuck., Gen. Lich. 196. 1872. 



Thallus thin, ashy gray, smooth to rough and scurfy, becoming chinky or some- 

 times granulose; apothecia small to middle-sized, 0.6-1.3 mm. across, sessile, round 

 or becoming flexuous or stellately lobed, the disk flat, chocolate brown and com- 

 monly whitish pruinose, the proper exciple erect, black, surrounded by a thick, 

 whitish, powdery, more or less disappearing, thalloid one; hypothecium brownish 

 black; spores fusiform, 3-septate, 24-40 X 4.5-6 /x. 



On trees, Florida and Texas. 



5. Schismatomma subattingens (Nyl.) Zahlbr., Cat. Lich. Univ. 2:565. 1924. 

 Platygrapha subattingens Nyl., Lich. Insul. Guin. 51. 1889. 



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

 coming powdery; apothecia small to middle-sized, 0.5-1 mm. across, round to 

 irregular, adnate to subsessile, the disk flat to slightly convex, brown, commonly 

 whitish pruinose, the proper exciple thin, brown, often disappearing, surrounded 

 by a thin, whitish, thalloid one; hypothecium dark brown; spores fusiform, some 

 slightly curved, 3-5-septate, 30-35 X 3.5-4 fx, parallelly to irregularly arranged. 



On trees, Florida. 



6. Schismatomma vernans (Tuck.) Zahlbr., Cat. Lich. Univ. 2:566. 1924. 

 Platygrapha vernans Tuck., Syn. N. A. Lich. 2:116. 1888. 



Thallus composed of minute, greenish gray granules, crowded at length into a 

 thin, rough crust; apothecia small to middle-sized, 0.4-0.8 mm. across, adnate to 

 sessile, round, the disk flat to convex, pale brown to black, somewhat grayish 

 pruinose, the thalloid exciple thin, colored like the thallus, becoming flexuous and 

 disappearing; hypothecium brownish black; spores ellipsoid to ellipsoid-fusiform, 

 3-septate, 13-18 X 4.5-6 ll. 



On charred wood, Florida. 



7. Schismatomma hypothallinum (Zahlbr.) Hasse, Cont. U. S Nat Herb 



17:32, 33. 1913. 



Platygrapha hypothallina Zahlbr., Bull. Torr. Club 27:645. 1900. Platygrapha 

 pinguis Tuck. 



Thallus thick, whitish, warty, folded and wrinkled, becoming pulverulent; 

 apothecia middle-sized to large, 0.5-1 mm. across or reaching 1.5 mm. across in 

 one direction, partly immersed to adnate, round to more or less irregular, the 

 disk flat to slightly convex, brownish to dull black, or more commonly whitish 

 pruinose, the thalloid exciple thick, colored like the thallus, becoming flexuous; 

 hypothecium dark brown to brownish black; spores oblong-fusiform 7-septate' 

 25-30 X 3-5 ll. 



On rocks and rarely on trees, southern California. 



8. Schismatomma pluriloculare Zahlbr., in E. & P., Nat. Pfl. 1:116. 1907. 

 Platygrapha plurilocularis Zahlbr., Beih. Bot. Central. 13:156, 157. 1902. 

 Thallus thick, smooth to rough, whitish to ashy, becoming warty to chinky, 



often limited by a black hypothallus; apothecia small to middle-sized, 0.5-2 mm! 

 across, sessile, often crowded, the disk flat, black or rarely whitish pruinose the 



