Hypotrachyna vainioi

Hypotrachyna vainioi has a corticolous thallus measuring 5–8 cm (2.0–3.1 in) wide. The individual lobes comprising the thallus are flat to somewhat convex with entire margins, and measure 0.4–1.2 cm (0.16–0.47 in) wide. The upper surface of the thallus is pale grey with a smooth to shallowly wrinkled texture. The thallus completely lacks soredia, isidia, pustules, dactyls (finger-like protrusions), and lobules. The medulla is white, while the lower surface is black to dark brown near the margins. The apothecia are 2–10 mm wide with a dark brown disc. Ascospores of H. vainioi are ellipsoid and measure 10–12 by 5–8 μm. ^[2]

Major secondary metabolites produced by the lichen are lichexanthone in the upper cortex, and echinocarpic acid in the medulla. Minor compounds include barbatic acid (minor), conechinocarpic acid (minor), subechinocarpic acid (minor), 4-O-demethylbarbatic acid (minor/trace), obtusatic acid (trace), and norobtusatic acid (trace).^[1]

It is only known from the type locality in Minas Gerais, Brazil. The type was collected in the Serra do Caraça [pt], near the Caraça monastery [pt], at an elevation of 1,300 m (4,300 ft).^[2] Hypotrachyna vainioi grows as an epiphyte in open scrubland.^[1]