380 43. BUELLIACEAE [ 172. Rinodina 



to moderately thick, colored like the thallus, becoming crenulate; hypothecium 

 hyaline to cloudy; spores ellipsoid, 16-24 X 8-11 (i. 

 On soil, southern California. 



25. Rinodina platyloba Willey, in Cummings, Williams and Seymour, Dec. N. A. 



Lich. no. 204. 



Thallus foliose, composed of thick, middle-sized to large, irregular, much folded, 

 broadly lobed, yellowish to ashy squamules; whitish within; apothecia middle-sized 

 to large, 1.5-3 mm. across, partly immersed, the disk concave to flat, black or 

 rarely grayish pruinose, becoming rough, the exciple thick, colored like the thallus, 

 wavy to crenate; hypothecium hyaline; spores oblong, constricted at the septum, 

 12-16 X 6-7.5fi. 



On rocks, southern California. 



26. Rinodina exigua (Ach.) S. F. Gray, Nat. Arr. Brit. PL 1:450. 1821. 

 Lichen exiguus Ach., Lich. Suec. 69. 1798. R. sophodes var. exigua (Ach.) Tuck. 

 Thallus thin, minutely granulose, the granules whitish to ashy gray or gray, 



more or less scattered, sometimes disappearing; apothecia minute to small, 0.15- 

 0.5 mm. across, adnate to sessile, sometimes crowded, the disk flat to convex, 

 blackish brown to black, the exciple thin, colored like the thallus, becoming 

 crenulate; hypothecium yellowish; spores 8- rarely 16 or more, ellipsoid to oblong- 

 ellipsoid, 11-20 X 6-10 /A. 



On old wood and trees, throughout the United States. 



27. Rinodina polyspora T. Fries, Arct. 126. 1860. 

 R. palustus Willey in litt. 



Thallus very thin, smooth to minutely granulose or warty, sometimes becom- 

 ing chinky, ashy or darker gray to whitish; bordered and sometimes intersected by 

 a black hypothallus; apothecia minute to small, 0.2-0.5 mm. across, adnate, the 

 disk flat to slightly convex, brownish black to black, the exciple thin, colored like 

 the thallus, becoming darker and sometimes disappearing; hypothecium hyaline; 

 spores 12-24, oblong or oblong-ellipsoid, some slightly curved, 13-16 X 6-8 /x. 



On trees, Massachusetts. 



28. Rinodina Conradi Koerb., Syst. Lich. 123. 1855. 



Thallus minutely granulose, the granules greenish gray to ashy or brownish, 

 flat or slightly convex, scattered or continuous and forming a thin, chinky to 

 areolate crust; apothecia small, 0.4-0.8 mm. across, sessile, the disk flat to slightly 

 convex, blackish brown to black, the exciple thick, colored like the thallus, becom- 

 ing crenulate; hypothecium yellowish; spores ellipsoid, 1-3-septate transversely and 

 the middle cells becoming 1-septate longitudinally, 18-32 X 9-14 (i. 



On rocks, Colorado, Washington, and California. 



29. Rinodina microbola Tuck.; Hedrick, Mycologia 26:164. 1934. 



Thallus thin, coarsely areolate, ashy to whitish, the areoles scattered or con- 

 tinuous; apothecia minute to small, 0.15-0.4 mm. across, partly immersed to 

 adnate, the disk flat to convex, black, the exciple thin, colored like the thallus; 

 hypothecium yellowish to brownish; spores ovoid-ellipsoid, 3-septate transversely 

 and becoming 1-septate longitudinally, 13-22 X 7-11 (i. 



On rocks, California. 



30. Rinodina oreina (Ach.) Mass., Ric. Lich. 16. f. 24. 1852. 

 Lecanora straminea var. oreina Ach., Lich. Univ. 433. 1810. 



Thallus thin to moderately thick, closely adnate, warty-areolate,. the areoles 

 small, greenish straw-colored to yellowish, passing into somewhat elongated, 

 branched, densely crowded, black-edged squamules toward the circumference; 

 apothecia minute to small, 0.2-0.75 mm. across, immersed to adnate or sessile, 

 the disk flat to slightly convex, black, the exciple thin, colored like the thallus, 



