11. Heterocarpon ] 2. DERMATOCARPACEAE 41 



10. Dermatocarpon Zahlbruckneri Hasse, Bryologist 16:2. 1913. 



Thallus areolate-squamulose, greenish gray, the squamules small, clustered, 

 convex, round or angular; perithecia large, 0.8-1.5 mm. across, 1-6 in each squam- 

 ule, the superficial portion dark brown to black, conical or flattened; asci becom- 

 ing saccate or ventricose; spores narrowly oblong-ellipsoid, 16-25 X 4-7.5 fx. 



On trap rock, Santa Monica Range, California. 



11. Dermatocarpon arboreum (Schwein.) Fink, Cont. U.S. Nat. Herb. 14:244. 



1910. 



Endocarpon arboreum Schwein., in E. Fries, Lich. Eur. 407. 1831. 



Thallus closely adnate or the margins slightly raised, squamulose-foliose, the 

 squamules small, clustered and more or less imbricated, or sometimes scattered, 

 the margins round, entire or lobed, pale olive-green to brownish; pale below with 

 darkening rhizoids; perithecia minute, 0.05-0.15 mm. across, numerous, immersed 

 in the thallus, only the brownish ostiole visible; spores ellipsoid, 10-15 X 4-6 ll. 



On trees, from Massachusetts to Florida and westward to Texas and Minne- 

 sota. 



12. Dermatocarpon Heppioides Zahlbr., Ann. Mycolog. 10:359. 1912. 

 Thallus thick, closely adnate, small to middle-sized, squamulose, hoary gray 



to brownish, the squamules irregular, running into convex, irregular warts toward 

 the center, flattened and imbricated toward the circumference, with sparingly lobed 

 and toothed margins; black and smooth below; perithecia minute, 0.08-0.2 mm. 

 across, immersed several in each squamule, only the minute ostiole visible; asci 

 clavate; spores oblong to oblong-ellipsoid, containing 1-3 oil globules, 16-24 X 

 6-10 /a, biseriately arranged. 



On sandstone, southern California. 



13. Dermatocarpon lecideoides (Mass.) Hasse, Bryologist 18:92. 1915. 

 Thrombium lecideoides Mass., Ric. Lich. 157. f. 305. 1852. 



Thallus thin, finely wrinkled, composed of small, flat, dark gray to blackening 

 areoles; perithecia minute, 0.1-0.2 mm. across, immersed, the apex hlack; spores 

 oblong-ellipsoid, 16-24 X 8-9.5 fi. 



On quartz, southern California. Doubtfully admitted, description adapted from 

 Hasse. 



OTHER SPECIES REPORTED 



Dermatocarpon peltatum (Tayl.) Zahlbr. — Arizona. 



11. Heterocarpon Mull. Arg., Flora 68:515. 1885. 



Thallus areolate, scaly, the areoles or scales often lobed, more or less densely 

 arranged, the upper cortex plectenchymatous, the lower cortex thin or wanting, 

 the algal and medullary layers more or less distinct; perithecia minute to small, 

 immersed, indicated by the small ostiole surrounded by the black exciple; hypo- 

 thecium brown; hymenium hyaline or brownish above; paraphyses becoming 

 indistinct; asci clavate; spores 6-8, brown or blackish, boat-shaped, ellipsoid or 

 fusiform, 1-3-septate. 



The algal host is Pleurococcus. 



1. Heterocarpon ochroleucum (Tuck.) Mull. Arg., Flora 68:515. 1885. 



Endocarpon ochroleucum Tuck., Gen. Lich. 250. 1872. 



Thallus thick, smooth, yellowish green, areolate, the areoles small and densely 

 arranged, usually convex, the central ones substipitate, those of the margin often 

 lobed; perithecia minute, 0.15-0.35 mm. across, immersed, 1-several in each areole. 

 the exposed portion and the whole exciple black; hypothecium brownish black; 

 spores boat-shaped, blackish, 18-25 X 3.5-5 fx. 



On rocks, California. 



