Inoderma afromontanum

The thallus (the lichen body) forms extensive, pale olivaceous-grey patches that can look matt, scurfy, or minutely granular; the surface lacks a true outer skin (it is ecorticate). The photosynthetic partner is a trentepohlioid green alga, with cells mostly 7–18 × 5–12 μm. A thin dark prothallus line may mark contact with neighbouring lichens. No calcium oxalate crystals were observed in the thallus.^[2]

Sexual fruiting bodies (apothecia) are small discs 0.5–0.8 mm across that sit level with or just above the thallus and are dusted with a thin white pruina (a frost-like powder). They are pale brown to brown and often broadly lobed. Internally, the spore-bearing layer is only moderately gelatinised; the tissue below it (hypothecium) is pale, and the asci are of the Arthonia-type. Ascospores are hyaline, narrowly obovate, with three cross-walls (3-septate), typically 8–10 × 3.5–4.0 μm, and have a slightly enlarged end cell. Standard iodine tests give coloured reactions in the gels of the fruiting body (I+ red; KI+ blue).^[2]

Asexual fruiting bodies (pycnidia) are numerous and conspicuous: dark brown to black cups 0.30–0.45 mm across that protrude from the thallus, their rims and shoulders coated in a white pruina. The opening is usually ragged and gaping. Inside, the wall is dark brown and the cavity is bowl- to cone-shaped, often partitioned by thin internal septa. The pycnidia produce abundant bacilliform conidia (asexual spores) that are about 3.7–5.1 × 1.1–1.7 μm. The species' chemistry is simple: 2'-O-methylperlatolic acid is present, while routine spot tests on the thallus and pruina are negative (K−, C−, KC−, Pd−).^[2]

Inoderma afromontanum is a tropical African species restricted to montane rainforest in Bwindi Impenetrable National Park, Uganda. It is rather common there between about 1,600 and 2,400 m and grows on the smooth to deeply fissured bark of large trees in mixed evergreen forest. Recorded substrates include Chrysophyllum albidum, Drypetes ugandensis and Leptonichia mildbraedii. As of its original description, it is the only Inoderma known from tropical latitudes. Localities documented span both the western (Buhoma) and eastern (Ruhija) sectors of the park.^[2]