10. Dermatocarpon ] 2. DERMATOCARPACEAE 39 



E. Thallus without rhizoids below 



F. Thallus reddish brown 8. D. rufescens 



F. Thallus gray to bluish or grayish pruinose .3. D. polyphyllum 



C. Spores 16-24 n in length 



D. Thallus dull greenish 9. D. squamellum 



D. Thallus hoary gray to brownish 12. D. Heppioides 



1. Dermatocarpon miniatum (L.) Mann, Lich. Bohem. 66. 1825. 



Lichen miniatus L., Sp. PL 1149. 1753. Endocarpon miniatum var. Muhlenbergii 

 (Ach.) Calkins. D. Muhlenbergii (Ach.) Mull. Arg. 



Thallus loosely adnate, large, rather thick, spreading, umbilicate, more or less 

 round, wrinkled or undulating, the margin entire or irregularly lobed, often re- 

 curved downward, ashy or bluish gray varying toward dusky brown; pale olive to 

 blackish brown below ; perithecia minute, 0.08-0.3 mm. across, immersed in the 

 thallus, only the dark ostiole visible; spores ellipsoid, 9-16X5-8 fx. 



On rocks, throughout the United States. 



var. complicatum (Light.) T. Fries, Nov. Act. Soc. Sci. Ups. III. 3:353. 1861. 

 Lichen miniatus var. complicatus Light., Fl. Scot. ed. 2. 858. 1777. 

 Thallus deeply divided, the divisions often extending almost to the umbilicus, 

 the lobes becoming much imbricated and sometimes severed from the plant. 

 On rocks, especially calcareous, widely distributed in the United States. 



var. fulvofuscum (Tuck.) Zahlbr. Cat. Lich. Univ. 1:229. 1921. 

 Endocarpon fluviatile var. fulvofuscum Tuck. Proc. Am. Acad. 1:275. 1848. 



Endocarpon miniatum fulvofuscum Tuck. 

 Reticulated and often yellowish brown below. 

 On rocks, from Maryland to Florida and westward to Colorado and Montana. 



2. Dermatocarpon aquaticum (Weis.) Zahlbr., Ann. Naturh. Hofmus. Vein 



16:81. 1901. 



Lichen aquaticus Weis., PI. Crypt. Gott. 77. 1770. (not L. 1753.) D. fluviatile 

 (Web.) T. Fries. D.manitense (Tuck.) Zahlbr. , 



Thallus small to middle-sized, thick, umbilicate, but many-lobed, becoming 

 tufted, lobes crowded, imbricated, margins round, entire or somewhat cut-lobulate, 

 ascending and recurved downward, ashy to olive- or dusky-brown; light brown 

 to blackish below; perithecia minute, 0.1-0.25 mm. across, immersed in the thallus, 

 only the minute dark ostiole visible; spores ellipsoid, 9-16 X 6-9 //.. 



On rocks, most commonly on those inundated or often wet, from New England 

 to Florida and westward to the Rocky Mountains, and in Nevada and California. 



3. Dermatocarpon polyphyllum (Wulf.) Dalla Torre & Sarnth., Fl. Grafs. 



Tirol 4:504. 1902. 



Lichen polyphyllus Wulf., Ges. Naturf. Freund. Mag. 8:142. 1787. D. intestini- 

 forme (Koerb.) Hasse. 



Thallus thick, tufted, middle-sized, squamulose, creamy gray to tinged bluish 

 or grayish pruinose, the squamules smooth to rough, small to middle-sized, crowded 

 into small, irregular areoles toward the center, expanded and imbricated toward 

 the circumference, with downward curved margins; brownish black and smooth 

 below; perithecia minute, 0.05-0.1 mm. across, immersed several in each areole or 

 squamule, the superficial portion depressed-convex, dull black, the ostiole minute, 

 brownish black; spores ellipsoid, 10-18 X 5-8.5 fi, uniseriately to irregularly ar- 

 ranged. 



On rocks, Arizona and California. 



4. Dermatocarpon hepaticum (Ach.) T. Fries, Nov. Act. Soc. Sci. Ups. III. 



3:355. 1861. 

 Endocarpon hepaticum Ach., Vet. Akad. Nya Handl. 156. 1809. D. Tuckermani 



(Rav.) Zahlbr. D. lachneum (Ach.) A. L. Smith. 

 Thallus closely adnate, squamulose, the squamules round to irregular, entire 

 to crenate, usually appressed, sometimes ascending and somewhat imbricated, red- 



