Protologue type data: Type: U.S.A. Texas. Hayes Co.: E side of Shade Road, S of CR 1492, 2 mi S of Wiberley on SR 12, 29°58'44.3"N, 98°06'26.4"W, Juniperus ashei forest on shaded calcareous rock, 17 Aug 2005, Amtoft 3600 (NY, holotype).

Type locality: USA, Texas, Hayes County, E side of Shade Road, S of CR 1492, 2 mi S of Wiberley on SR 12, Juniperus ashei forest on shaded calcareous rock, 17 August 2005, Amtoft 3600 (NY - holotype).

Type locality coordinates: 29°58'44.3"N, 98°06'26.4"W.

ITS barcode: Data lacking.

Description: Lichen. Thallus single-lobed, 0.75-4.5 cm wide, thin, ca. 200-380 µm thick, with a single, marginal or central umbilicus; margin even to slightly lobulate in older thalli; upper side pale grayish or greenish brown to brown, often with a slightly pruinose appearance or farinose surface; lower side minutely tomentose with infrequent bald (tomentum-free) areas; tomentum dark brown; bald areas paler than tomentum and pale reddish brown. Lower cortex with basal cells brown, proliferating in groups or singly and giving rise to a tomentum composed of moniliform hyphae, 44.0-187.- x (4.4-)6.6-12.1 µm, concolorous with the brown pigment deposited on the surface of the basal cortical cells, unbranched or branched, entangled or not, with the cells arranged in a single plane, one to several cells wide at the base, sometimes more than one cell wide above the base; these cells spherical to subcuboidal, with the ultimate cell sometimes obtusely tapered. Medulla loose and somewhat glassy, of hyphae 3-5 µm wide. Perithecia common, 220-262 x 209-220 µm, with a hyaline exciple; ostiole dark to light brown around the mouth and level with or slightly immersed in the upper surface. Spores (8.8-)11.0-13.2 x 4.4-5.5(-6.6) µm biseriate. Pycnidia immersed, uncommon, only immature ones found (Amtoft 2006: 182).

Photobiont: Green alga.

Chemistry: No lichen substances.

Ecology: On calcareous in moderately shaded habitats and Juniperus ashei forests (Amtoft 2006: 184).

Distribution type: Subtropical to tropical. Southern North America and Caribbean. USA: Texas, USA: Missouri, Bahamas: Cat Island, and Bahamas: New Providence.

Taxonomy: Based on both morphological and molecular data Dermatocarpon tomentulosum is closely related to D. moulinsii and D. reticulatum. Dermatocarpon moulinsii and D. schaechtelinii both bear robust rhizinomorphs composed of cylindrical aggregations of cells which are distinctly different from the delicate hyphae that compose the tomentum in D. tomentulosum. Dermatocarpon reticulatum is distinguished from all three species by a lower surface with short, angular papillae. All four species are similar in bearing perithecia with an ostiole and ostiole mouth that is most often immersed or level with the upper surface (Amtoft 2006: 184).

Note: The species is not a North American endemic as the Bahamas are part of Middle America.

Distribution Database: Distributions

Distribution Database: Discover Life

Picture Database: Tropical Lichens

Molecular Database: Genbank

Synonym Database: Index Fungorum

Synonym Database: Mycobank