42 2. DERMATOCARPACEAE [12. Endocarpon 



12. Endocarpon Hedw.. Descr. Muse. Frond. 2:56. pi. 20, f . a. 1789. 



Thallus crustose, with algal, medullary, and upper cortical layers well developed, 

 minutely squamulose, squamules round to more or less irregular, scattered or 

 clustered, closely attached by rhizoids; perithecia minute to small, immersed, 1 

 to several or many in a squamule, only the minute, dark ostiole visible, the wall 

 dimidiate; paraphyses soon gelatinizing; asci clavate; spores 2-4 or rarely 6, hya- 

 line to brown, oblong to ovoid-ellipsoid, transversely and longitudinally septate, 

 uniseriately to irregularly arranged. 



The algal host is Pleurococcus. 



A. Thallus areolate or the squamules passing into an areolate crust 



B. Thallus dusky olive-green to blackish 4. E. Wilmsoides 



B. Thallus olive-gray to ashy or dusky gray 5. E. Monicae 



A. Thallus more or less persistently squamulose 

 B. Spores not more than 13-septate transversely 

 C. Thallus of small, more or less lobed squamules 



D. Thallus pale reddish brown or lighter colored . . . . 6. E. pallidum 

 D. Thallus light brown to olive- or dusky-brown .... 1. E. pusillum 

 C. Thallus of small, twisted and knotted, often- 

 stalked squamulose 7. E. tortuosum 



B. Spores commonly more than 13-septate transversely 



C. Spores 46-70 /j. in length 2. E. subnitescens 



C. Spores 28-40 fi in length 3. E. lepidallum 



1. Endocarpon pusillum Hedw.. Descr. Muse. Frond. 2:56. pi. 20, f. a. 1789. 



E. pusillum var. Garovaglii (Mont.) Willey. E. Sckaereri (Koerb.) Fink. 



Thallus rather thick, squamulose, closely adnate, the squamules minute, scat- 

 tered, or clustered and forming an areolate surface, or becoming more or less 

 lobed and imbricated, the smaller ones round, the larger irregular, light brown to 

 olive- or dusky-brown; perithecia minute, 0.08-0.2 mm. across, immersed, often 

 several in a squamule, the dark ostiole protruding slightly, the wall dimidiate; 

 spores usually 2, hyaline to brownish, oblong, 7-13-septate transversely and 

 2-3-septate longitudinally, 23-45 X 12-18 /a, uniseriately arranged. 



On soil and rocks, throughout the United States east of the Rocky Mountains, 

 and in Nevada and California. 



2. Endocarpon subnitescens Nyl., in Hue, Rev. Bot. 6:103. 1888. 



Verrucaria subnitescens Nyl., Flora 68:299. 1885. 



Thallus thin, composed of small, lobulate, reddish brown squamules; perithecia 

 minute, 0.14-0.2 mm. across, immersed, often several in each squamule, indicated 

 by a minute darker depression, the wall dimidiate; spores 2, hyaline to pale brown, 

 oblong, 17-23-septate transversely and 3-7-septate longitudinally, 46-70 X 18-24 /x, 

 uniseriately arranged. 



On soil, southern California. 



3. Endocarpon lepidallum Nyl., in Hasse, Lich. South. Calif, ed. 2. 17. 1898. 

 Thallus thin, composed of small, round to wavy and lobulate, whitish to smoky 



gray squamules, the margin often ascending or recurved and blackening; perithecia 

 minute, 0.08-0.1 mm. across, immersed, 1-12 or more in a squamule, indicated 

 by the minute, protruding gray apices, the wall dimidiate; spores 2, hyaline to 

 brown, oblong to ovoid-ellipsoid, 11-17-septate transversely and 5-7-septate longi- 

 tudinally, 28-40 X 14-18 fi, irregularly arranged. 

 On soil, southern California. 



4. Endocarpon Wilmsoides Zahlbr., Beih. Bot. Centralb. 13:152,153. 1902. 



Thallus in small, round areas, scattered or confluent, minutely chinky to 

 chinky-areolate, dusky olive-green to blackish; perithecia minute to small, 0.2- 

 0.4 mm. across, immersed, except the minute ostiole, 1 or 2 in each small, sub- 

 hemispherical raised area, the wall dimidiate; spores 2, hyaline to brown, ovoid 

 to oblong-ovoid, 7-11-septate transversely and 2-4-septate longitudinally, 33-48 X 

 13-20 /a, uniseriately arranged. 



On argillaceous schist, southern California. 



