1. Verrucaria ] 1. VERRUCARIACEAE 31 



4. Verrucaria maura Wahl., in Ach., Meth. Lich. Suppl. 19. 1803. 



V. maura var. aractina (Wahl. ) Torss. 



Superficial thallus thin or somewhat thickened, smooth, minutely chinky- 

 areolate to rough- verrucose, grayish- or brownish-black to black; perithecia small 

 to middle-sized, 0.3-0.6 mm. across, immersed, except the black apex, in sub- 

 hemispherical to hemispherico-conoid raised areas; spores oblong to ellipsoid, 

 9-17 X 5-9 p. 



On rocks along the seashore, Maine, Massachusetts, Rhode Island, Washington, 

 and California. 



5. Verrucaria mucosa Wahl., in Ach.. Meth. Lich. Suppl. 23. 1803. 



V. ceuthocarpa var. mucosa (Wahl.) Tuck. 



Superficial thallus thin or sometimes rather thick, smooth, sometimes chinky, 

 olive-green to greenish black or lead-colored; perithecia minute, 0.08-0. IS mm. 

 across, appearing as black spots in the thallus, sometimes protruding; spores 

 ellipsoid, 7-15 X 4-8 p. 



On wet or submerged rocks, Maine, Massachusetts, and New York, usually 

 along the seashore. 



6. Verrucaria aethiobola Wahl.. in Ach., Meth. Lich. Suppl. 17. 1803. 



Superficial thallus thin, in small areas or rather widespread, sometimes some- 

 what chinky, olive-green to tan or ashy; perithecia minute to small, 0.1-0.4 mm. 

 across, at first largely immersed in raised areas, later more or less exposed, the 

 superficial portion subhemispherical. somewhat shining, black; spores oblong to 

 ellipsoid or rarely subovoid, 14-20 X 5-8 /x. 



On argillaceous rocks, Massachusetts, Illinois, and southern California. 



7. Verrucaria silicicola Fink*; Hedrick, Mycologia 25:305. 1933. 



Thallus thin to moderately thick, smooth to rough, becoming chinky, sometimes 

 appearing minutely granulose, dark greenish gray to black; perithecia minute to 

 small, 0.15-0.4 mm. across, scattered or more or less clustered, immersed to partly 

 superficial, the wall dimidiate and centrally open below, the superficial portion 

 subhemispherical or subconical, dull black, the ostiole minute, often scarcely 

 visible; spores oblong-ellipsoid, 18-22 X 8-9 /x, irregularly arranged. 



On a littoral quartz pebble. Long Island, New York. 



8. Verrucaria papillosa Ach., Lich. Univ. 286. 1810. 



V. margacea var. papillosa (Ach. ) Leight. 



Superficial thallus thin, widespread, becoming chinky and somewhat wrinkled, 

 greenish brown or darker; perithecia minute, 0.1-0.16 mm. across, immersed in 

 warts, the upper portion protruding, black; spores ovoid-ellipsoid, 16-22 X 6-10 p. 



On argillaceous rocks, southern California. 



9. Verrucaria hydrela Ach., Syn. Meth. Lich. 94. 1814. 



V. margacea var. hydrela Torss. 



Superficial thallus thin or becoming thicker, usually widespread, smooth, some- 

 times chinky, olive-green to brownish; perithecia small to middle-sized, 0.2-0.5 mm. 

 across, immersed in the thallus except the dark apex; spores ellipsoid, 19-34 X 

 9-17 p. 



On rocks, Washington. 



10. Verrucaria margacea Wahl.. Fl. Lapp. 465. 1812. 



Thelotrema margaceum Wahl., in Ach., Meth. Lich. Suppl. 30. 1803. V. margacea 

 subsp. terrestris Nyl. 



Superficial thallus rather thick or sometimes thinner or disappearing, chinky, 

 usually widespread, olive- to grayish-brown; perithecia small to middle-sized, 

 0.3-0.5 mm. across, at first immersed in raised areas, the black apex later more or 



* Misspelled V. silicola. in earlier publication. 



