{{Short description|Species of lichen}} {{Use dmy dates|date=September 2025}} {{Use Oxford spelling|date=September 2025}} {{Speciesbox | image = | image_caption = | taxon = Inoderma afromontanum | authority = Frisch & G.Thor (2015) | mapframe = yes | mapframe-zoom = 4 | mapframe-coordinates = {{coord|01|01|00|S|29|37|30|E}} | mapframe-caption = Holotype: Buhoma, Uganda }}

'''''Inoderma afromontanum''''' is a species of corticolous (bark-dwelling) crustose lichen in the family Arthoniaceae.<ref name="CoL_6MVT3"/> Found in Uganda's Bwindi Impenetrable National Park, it was described from specimens collected in the park's montane rainforest. It is distinguished by its conspicuous dark pycnidia (asexual fruiting bodies) with white frost-like coating and its simple chemistry. ''I.&nbsp;afromontanum'' is the only known tropical member of the genus ''Inoderma'', which otherwise consists of temperate species.

==Taxonomy==

''Inoderma afromontanum'' was formally described as new to science in 2015 by Andreas Frisch and Göran Thor as part of a revision that resurrected the genus ''Inoderma'' for a small group of species characterised by elevated, white, frost-edged ({{lichengloss|pruinose}}) asexual structures and pallid, pruinose sexual structures. The specific epithet refers to its afromontane rainforest habitat. The holotype was collected on rough bark along the Waterfall Trail near Buhoma in Bwindi Impenetrable National Park, south-western Uganda, at 1,600–1,700 m elevation. The paper's phylogenetic analyses place ''Inoderma'' within the {{lichengloss|cryptothecioid}} subclade of family Arthoniaceae.<ref name="Frisch et al. 2015"/>

Within the genus, ''I.&nbsp;afromontanum'' is set apart by its chemistry and morphology. It contains 2'-''O''-methylperlatolic acid as its only detected secondary metabolite (the usual quick spot tests on the thallus and pruina are negative), has small ascospores with three septa, and shows pale rather than dark brown tissue beneath the spore layer in the fruiting bodies. It differs from the temperate ''I.&nbsp;byssaceum'' by its chemistry and by having immersed, only slightly convex apothecia with often lobed margins; it differs from ''I.&nbsp;subabietinum'' and ''I.&nbsp;nipponicum'' in a combination of chemistry and pycnidial details.<ref name="Frisch et al. 2015"/>

==Description==

The thallus (the lichen body) forms extensive, pale olivaceous-grey patches that can look matt, scurfy, or minutely {{lichengloss|granular}}; the surface lacks a true outer skin (it is {{lichengloss|ecorticate}}). The photosynthetic partner is a {{lichengloss|trentepohlioid}} green alga, with cells mostly 7–18 × 5–12&nbsp;μm. A thin dark prothallus line may mark contact with neighbouring lichens. No calcium oxalate crystals were observed in the thallus.<ref name="Frisch et al. 2015"/>

Sexual fruiting bodies (apothecia) are small discs 0.5–0.8&nbsp;mm across that sit level with or just above the thallus and are dusted with a thin white {{lichengloss|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 ({{lichengloss|hypothecium}}) is pale, and the asci are of the ''Arthonia''-type. Ascospores are hyaline, narrowly {{lichengloss|obovate}}, with three cross-walls (3-septate), typically 8–10 × 3.5–4.0&nbsp;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).<ref name="Frisch et al. 2015"/>

Asexual fruiting bodies (pycnidia) are numerous and conspicuous: dark brown to black cups 0.30–0.45&nbsp;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 {{lichengloss|bacilliform}} conidia (asexual spores) that are about 3.7–5.1 × 1.1–1.7&nbsp;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−).<ref name="Frisch et al. 2015"/>

==Habitat and distribution==

''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&nbsp;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.<ref name="Frisch et al. 2015"/>

==References== {{Reflist|refs=

<ref name="CoL_6MVT3">{{Catalogue of Life |id=6MVT3 |title=''Inoderma afromontanum'' Frisch & G. Thor |access-date=11 September 2025}}</ref>

<ref name="Frisch et al. 2015">{{cite journal |last1=Frisch |first1=Andreas |last2=Ohmura |first2=Yoshihito |last3=Ertz | first3=Damien |last4=Thor |first4=Göran |title=''Inoderma'' and related genera in Arthoniaceae with elevated white pruinose pycnidia or sporodochia |journal=The Lichenologist |volume=47 |issue=4 |year=2015 |doi=10.1017/s0024282915000201 |pages=233–256 |bibcode=2015ThLic..47..233F }}</ref>

}}

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Category:Arthoniaceae Category:Lichen species Category:Lichens described in 2015 Category:Lichens of East Tropical Africa Category:Taxa named by Andreas Frisch Category:Taxa named by Göran Thor