Sporopodium soredioflavescens

The thallus of Sporopodium soredioflavescens is crustose (crust-like), continuous, and dull, forming a pale greenish film up to about 4 cm (1.6 in) across and under 0.1 mm thick; it lacks a cortex (a distinct outer layer). The surface has even paler, hemispherical warts about 0.05 mm wide, spaced roughly 0.1 mm apart, and lacks a distinct prothallus (a border of fungal tissue). The thallus bears soralia (patches that produce soredia), mostly towards the thallus margin. The soredia form a powdery (farinose) layer that is slightly darker green than the surrounding thallus and lies on the surface. The photobiont (algal partner) is trentepohlioid (Trentepohlia-type). Sexual fruiting bodies (ascomata) have not been observed. Campylidia are present and stain blue with iodine (IKI+). They are 0.2–0.3 mm in diameter and up to 0.3 mm high, strongly concave, deep yellow inside and pale yellow outside, and attached to the thallus by a white hyphal base. Asexual spores (conidia) have not been observed. All standard spot tests were negative (UV–, C–, P– and K–). Thin-layer chromatography was not performed because too little material was available. The yellow pigment was inferred to be a xanthone based on its colour and comparison with other Sporopodium species.^[1]

Sporopodium soredioflavescens grows on living leaves in primary rain forest in the Reserva Cristalino region of Mato Grosso, Brazil, at elevations between about 250 and 350 m (820 and 1,150 ft). When it was described in 2022, it had not been reported from outside Brazil.^[1] Later records extended its known range to São Paulo state.^[2][3]