310 38. LECANORACEAE [ 144. Icmadophila 



A. Disk divided by inward extensions of the exciple . . . .2.0. pallescens rosella 



A. Disk not so divided 



B. Thallus of conglomerate granules or short coralloid branchlets . 1. O. tartarea 

 B. Thallus chinky to areolate, becoming folded and wrinkled . . 2. O. pallescens 



1. Ochrolechia tartarea (L.) Mass., Ric. Lich. 30. 1852. 



Lichen tartareus L., Sp. PI. 1141. 1753. Lecanora tartarea var. gonatodcs Ach. 

 Lecanora tartarea (L.) Ach. 



Thallus thick, composed of rough, uneven, conglomerate and often heaped, 

 whitish to darker ashy granules or short coralloid branchlets; apothecia middle- 

 sized to large, 1-3 mm. across, adnate to sessile, the disk concave to flat, yellowish 

 brown to brick-colored, the exciple thick, colored like the thallus, becoming flexu- 

 ous; spores ellipsoid to oblong-ellipsoid, 30-65 X 20-35 /x. 



On trees and rocks, throughout the United States. 



2. Ochrolechia pallescens (L.) Mass., Ann. Sci. Nat. Bot. 7:212. 1853. 

 Lichen pallescens L., Sp. PI. 1142. 1753. Lecanora pallescens (L.) Rohl. 



Lecanora pallescens var. upsaliensis (L.) Flot. 0. upsaliensis (L.) Mass. 



Thallus moderately thick, smooth, chinky to areolate, becoming folded and 

 wrinkled, rarely warty or tuberculate, whitish to darker gray; apothecia middle- 

 sized, 1-2.5 mm. across, adnate, the disk more or less concave to flat, flesh-colored 

 to whitish or yellowish, usually more or less whitish pruinose, the exciple thick, 

 colored like the thallus, sometimes rough and warty; spores ellipsoid to ovoid- 

 ellipsoid, 40-75 X 20-35 /x. (Plate 31.) 



On trees, throughout the United States. 



var. rosella (Tuck.) Zahlbr., Cat. Lich. Univ. 5:686. 1928. 

 Lecanora pallescens var. rosella Tuck., Gen. Lich. 125. 1872. 

 The disk divided into areas by inward extensions of the exciple. 

 On trees and rarely on rocks, throughout northern United States. Not common. 



144. Icmadophila Ehrh., Beitr. Naturk. 4:147. 1789. 



Thallus crustose, closely attached to the substratum, devoid of differentiation 

 into layers; stipes very short or wanting; apothecia middle-sized to large, sessile 

 or on apex of stipe, the disk flat to convex, the exciple thin, colored like the disk, 

 surrounded by a thin to thick, soon disappearing, thalloid one; hypothecium 

 hyaline; hymenium hyaline or brownish above; paraphyses unbranched; asci 

 cylindrical; spores 8, hyaline, 1-3-septate. 



The algal host is Pleurococcus. 



1. Icmadophila ericetorum (L.) Zahlbr., Wiss. Mitteil. Bosn. Here. 3:605. 1895. 



Lichen ericetorum L., Sp. PI. 1141. 1753. I. aeruginosa (Scop.) Trevis. Baeomy- 

 ces aeruginosus (Scop.) DC. Lecidea icmadophila (L.) Ach. 



Thallus thin to moderately thick, rough, granulose or somewhat warty, rarely 

 becoming scurfy, greenish gray to greenish or whitish; apothecia middle-sized to 

 large, 0.6-3.5 mm. across, sessile or borne on very short stipes, the disk flat to 

 slightly convex, pale to rosy flesh-colored, becoming more or less wrinkled, sur- 

 rounded by a thin proper exciple, the thalloid exciple thin to rather thick, becom- 

 ing flexuous and sometimes disappearing; spores oblong, fusiform, 1-3-septate, 

 14-28 X 4-6 ii. (Plate 32.) 



On soil and old wood, from New England westward to the Pacific coast. 



145. Lecania Mass., Gen. Lich. 12. 1855. 



Thallus crustose, uniform, devoid of differentiation into layers, or showing 

 poorly developed, indistinct upper cortex, algal and medullary layers, and attached 

 to the substratum by hyphal rhizoids; apothecia minute to small or middle-sized, 

 adnate to sessile, the disk concave to flat or more or less convex, the exciple 

 colored like the thallus, often disappearing; hypothecium hyaline; hymenium hya- 



