Cora boleslia

The thallus of Cora boleslia is epiphytic and foliose, forming rosettes up to 5 cm across on shaded twigs. It comprises two to five semicircular lobes, 1–2 cm wide and 0.7–1.5 cm long, which remain unbranched and lack radial sutures. When fresh the upper surface is a uniform aeruginous green, even and glabrous, with thin, inward-rolled (involute) margins that soon fade to grey in the herbarium; no concentric undulations develop. Drying renders the surface gently wrinkled (rugose. The lower face lacks a cortex (it is ecorticate) and shows a whitish, felty-arachnoid medulla.^[2]

Vertical sections are 150–200 micrometres (μm) thick. A viaduct-shaped upper cortex, 20–30 μm deep, overlies a 30–50 μm zone of loosely anticlinal hyphae. The photobiont layer, 50–80 μm thick, is aeruginous throughout, while the medulla, 20–50 μm, is hydrophobic and bears numerous papilliform-to-coralloid hyphae 2–3 μm wide. Clamp connections are absent, and no hymenophore was observed in the available material. Thin-layer chromatography detected no secondary metabolites.^[2]

Cora boleslia is known only from the type locality in humid montane rainforest at about 2,200 m elevation in the Central Andes of Bolivia. It grows epiphytically on slender twigs under partial shade, where persistent cloud cover, high moisture, and moderate temperatures prevail. The even, hydrophobic thallus surface may aid rapid shedding of water in these mist-laden forests, while the absence of concentric undulations distinguishes it from similarly coloured Andean members of the genus.^[2] Cora boleslia is one of 11 Cora species that have been documented to occur in Bolivia.^[3]