Lecidella fuliginea

Lecidella fuliginea was described in 2022 by André Aptroot and Lidiane Alves dos Santos from material collected on tree bark in rainforest at Santuário do Caraça, Minas Gerais, Brazil, at elevation. The holotype (A. Aptroot 52200 & L.A. dos Santos), the reference specimen for the name, is held in the herbarium of the (ISE). An isotype (a duplicate specimen) in kept the herbarium of the Federal University of Mato Grosso do Sul (CGMS). Within Lecidella, the species is externally similar to Lecidella elaeochroma but more similar internally to Lecidella violaceofuliginea. It shares violet pigmentation and a densely inspersed hymenium (the spore-bearing layer) with L. violaceofuliginea. Comparison with L. violaceofuliginea from the same locality (topotype material, collected at the type locality) indicated that L. fuliginea is closely related but differs in its smaller thallus and apothecia, and in having a xanthone in the thallus. These differences support treating it as a distinct species. ==Description==

The thallus of Lecidella fuliginea is crustose and cracked into minute (small angular surface patches). It forms a slightly glossy, pale greenish crust up to about across and roughly 0.1 mm thick, bordered by an thin black line about 0.2 mm wide. It has a (outer layer), and the (algal partner) is . The fruiting bodies (ascomata) are solitary, (sitting directly on the surface), and not constricted at the base. They are round to somewhat lobed, 0.2–1.4 mm in diameter and about 0.2 mm high. The (central surface) is flat and purplish brown to black, and it is not (not powdery). The glossy margin is the same colour as the disc, slightly raised, and about 0.05 mm wide. In microscopic section, the is brown, the grey, and the red-brown. The (tissue between the asci) is densely with hyaline (colourless) oil droplets, and it turns blue with iodine (IKI+). Ascospores are produced eight per ascus. The spores are hyaline, simple, long-ellipsoid, and measure 13–16 × 7–8.5 μm. They lack a surrounding gelatinous sheath. Pycnidia have not been observed. In standard spot tests, the thallus is UV+ (pink) but negative in the C, K, KC, and P tests. Thin-layer chromatography detects a xanthone as the main lichen substance, interpreted as 4,5-dichloronorlichexanthone. ==Habitat and distribution==

Lecidella fuliginea is known from its type locality (the place where the type specimen was collected) in the Santuário do Caraça area of Minas Gerais in southeastern Brazil. There it grows on tree bark in primary rain forest at elevations between about . As the time of its original publication, it had not been reported from outside Brazil. As of 2025, no additional records had been reported. ==References==