Eschatogonia minuta

The thallus forms loosely effuse patches of minute squamules 0.3–0.6 mm across. Each squamule quickly splits into a tuft of branch-like lobes that are mostly flat near their base but soon become half-round (terete) and ascend, giving the entire lichen a coral-like appearance. The upper surface is dull green, free of any frost-like coating (pruina) and unmarked by spots; the squamule margins are the same colour as the upper surface. Unlike several other Eschatogonia lichens, E. minuta produces no marginal lobules and its inner tissue (medulla) lacks the needle-shaped crystals that dissolve in potassium hydroxide solution, a standard spot test in lichenology.^[2]

Fruiting bodies (apothecia) are uncommon. When present they appear as solitary or weakly clustered discs up to 0.6 mm in diameter that start pale brown and become slightly domed with age; their rim is poorly developed and may become notched (emarginate). The spores are simple or faintly one-septate, slender cylinders about 1.5 μm thick and 16–25 μm long (measured in water from forty spores). No asexual propagules (pycnidia) have been observed, and repeated chromatographic surveys confirm that the thallus is chemically negative for all standard lichen products.^[2]

Eschatogonia minuta inhabits humid, shaded trunks in primary lowland to lower-montane rainforest. It has been recorded from four departments in the Peruvian Amazonia between roughly 100 and 1200 m elevation, with additional collections from El Salvador, Venezuela, and French Guiana.^[2] It was reported from the West Indies (Trinidad),^[3] and from Brazil in 2023.^[4] All Peruvian sites lie in undisturbed forest, where the lichen grows on the lower bark of standing trees, often among mosses and other corticolous lichens.^[2]

Although the species' overall range is probably broader than the present herbarium record, its reliance on shaded, consistently moist microhabitats suggests some sensitivity to canopy opening and bark desiccation. Within suitable rainforest, however, E. minuta can be locally frequent and sometimes co-occurs with E. angustiloba and E. prolifera, indicating that fine-scale niche partitioning—rather than broad ecological separation—may allow several Eschatogonia species to share the same substrate.^[2]