Thallus smooth, roughened, or verrucose, in some species chinky to areolate, or even subsquamulose, rarely rudimentary and evanescent; apothecia minute to middle-sized, usually adnate, but rarely sessile or immersed, with pale to black, and flat to strongly convex disk; exciple and hypothecium from pale to dark brown in section; hymenium lighter, most commonly pale; spores simple, hyaline, 8 in each ascus.
KEY TO THE SPECIES OF LECIDEA
| Exciple soft, usually light colored. | |
| Apothecia usually surrounded by a thalloid veil | 1. L. coarctata |
| Apothecia not surrounded by a thalloid veil. | |
| Exciple becoming covered. | |
| Hypothecium pale or pale yellow. | |
| Apothecia always minute. | |
| Spores 5 to 7 mic. long | 2. L. intropallida |
| Spores 7 to 15 mic. long | 3. L. varians |
| Apothecia reaching middle size | 4. L. rupestris |
| Hypothecium light-brown to dark brown. | |
| Thallus gray-green or lighter | 5. L. viridescens |
| Thallus darker from the first or becoming so. | |
| Thallus minute and evanescent | 6. L. humicola |
| Thallus well developed and persistent. | |
| Thallus of raised granules | 7. L. uliginosa |
| Thallus of flat granules | 8. L. sylvicola |
| Exciple persistent | 9. L. flexuosa |
| Exciple horny, dark colored. | |
| Disk usually convex, commonly on wood | 10. L. enteroleuca |
| Disk flat or less commonly convex, on rocks. | |
| Disk usually white- to rusty-green-pruinose | 11. L. albocaerulescens |
| Disk black, scarcely pruinose | 12. L. platycarpa |
1. Lecidea coarctata (J.E. Smith) Nyl. Act. Soc. Linn. Bord. 21: 358. 1856.
Lichen coarctatus J.E. Smith in Sowerby, Eng. Bot. 8: pl. 534. 1789.
Thallus of minute, scattered or clustered, rounded, angular, or minutely and irregularly crenate, green-gray, pale brown, or more commonly ash-white granules, sometimes passing into a subcontinuous, chinky or areolate crust; apothecia minute to small, 0.2 to 0.4 mm. in diameter, adnate, from flesh-colored to black, commonly concave or flat, sometimes difform, frequently surrounded laterally by a thalloid veil; hypothecium and hymenium pale to pale brown; paraphyses distinct; asci clavate or cylindrico-clavate; spores ovoid to ellipsoid, 13 to 23 mic. long and 7 to 10 mic. wide.
Collected in Lake, Ross, Hocking, and Preble counties. Also examined from Lawrence County. On rocks and old bricks. Not previously reported from Ohio. Widely distributed in the State, but rare, except in Lake County, where this fungus was unusually common.
2. Lecidea intropallida sp. nov.
Thallus a continuous, smooth or slightly roughened, ash-gray and darkening crust; apothecia minute, 0.15 to 0.25 mm. in diameter, adnate or partly immersed, flesh-colored to yellow-brown, flat to slightly convex, the concolorous and inconspicuous exciple soon covered; hypothecium and hymenium pale; paraphyses sometimes distinct, but more commonly coherent-indistinct; asci clavate; spores simple, hyaline, ellipsoid, 5 to 7 mic. long and 2.5 to 3 mic. wide.