13. Pyrenothamnia ] 3. PYRENOTHAMNIACEAE 43 



5. Endocarpon Monicae Zahlbr., Beih. Bot. Centralb. 13:153. 1902. 



Thallus thin, widespread, squamulose, the squamules minute, forming an areo- 

 late crust, becoming swollen when moist, olive-gray or ashy to dusky gray; peri- 

 thecia minute, 0.1-0.25 mm. across, immersed, 1 or 2 in each squamule, indicated 

 by the protruding black apices, the wall dimidiate; spores 2-3, ovate to oblong, 

 8-15-septate transversely and 2-4-septate longitudinally, 25-50 X 1 1—19 /x, irregu- 

 larly arranged. 



On argillaceous schist, southern California. 



6. Endocarpon pallidum Ach., Lich. Univ. 301. 1810. 



Thallus thin, composed of small, lobed and sometimes imbricate, often scat- 

 tered, pale reddish brown or lighter colored squamules ; perithecia minute to small, 

 0.1-0.3 mm. across, immersed, 1-10 or rarely more in a squamule, indicated by 

 the protruding brownish black apices, the wall dimidiate; spores 2, brown, oblong, 

 7-13-septate transversely and 3-7-septate longitudinally, 36-52 X 14-18 /a, uni- 

 seriately arranged. 



On soil, New England and California. 



7. Endocarpon tortuosum Herre, Bot. Gaz. 51:288. 1911. 



Thallus thin, composed of small, irregular, twisted and knotted, often stalked 

 and erect, lobulate, ashy brown to darker, imbricate-foliose, scattered or clustered 

 squamules; perithecia minute, 0.05-0.1 mm. across, immersed, the ostiole not 

 plainly visible, the wall dimidiate; spores 2, hyaline to brown, ellipsoid to oblong- 

 ellipsoid, 7-11-septate transversely and 1-3-septate longitudinally, 45-60 X 18—26 yu.. 



On rocks, Nevada and Montana. 



OTHER SPECIES REPORTED 



Endocarpon petrolepideum (Nyl.) Hasse — California. 

 Endocarpon pulvinatum T. Fries — California. 



3. PYRENOTHAMNIACEAE 



Thallus fruticose, more or less branched, differentiated into a well-developed 

 cortex surrounding a loosely interwoven medulla; perithecia immersed, single, 

 upright, the ostiole terminal. 



The algal host is Pleurococcus. 



13. Pyrenothamnia Tuck., Bull. Torr. Club 10:22. 1883. 



Thallus fruticose, caespitose, dilated or dichotomously branched above, the 

 plectenchymatous cortex surrounding a loosely interwoven medulla; perithecia 

 minute, immersed in warts on the upper side of the branches, the wall complete; 

 hypothecium hyaline to brownish; paraphyses soon coherent, gelatinized and dis- 

 appearing; asci clavate to inflated-clavate; spores 1-4, ellipsoid, brown to blackish 

 brown, transversely and longitudinally septate. 



The algal host is Pleurococcus and occurs in the medulla and in the hymenium. 



A. On rocks; thallus crowded into an irregular crust 2. P. Brandegei 



A. On soil; thallus not crowded into a crust 1. P. Spraguei 



1. Pyrenothamnia Spraguei Tuck., Bull. Torr. Club 10:22, 23. 1883. 



Thallus composed of short, erect, slender, crowded, ashy brown to blackish, 

 dichotomously much-branched stalks, the branches dilated above, the tips becoming 

 crenate; perithecia minute, 0.1 5-0.3 mm. across, immersed, the ostiole closed, sur- 

 rounded by a depressed, sometimes lighter colored area, the wall complete, hyaline 

 to slightly tinged with brown; asci inflated-clavate; spores 1-4, brown, broadly 

 ellipsoid, 7-11-septate transversely and 2-5-septate longitudinally, 28-52 X 18-24 fx. 



On moss, Washington. 



