Cresponea pallidosorediata

The thallus is crustose and continuous, forming a dull, pale olivaceous-brown layer up to about 0.1 mm thick. It lacks a cortex and is not bordered by a distinct prothallus It bears abundant soredia that develop in tiny, point-like soralia and soon become granular and widespread, often covering most of the thallus surface. The photobiont is trentepohlioid (a member of the green algal genus Trentepohlia). The ascomata are solitary and sit on the thallus surface, with a constricted base. They are round, 0.7–1.3 mm in diameter and about 0.3 mm high. The disc is black and usually coated with a thin golden-yellow pruina; the black margin is raised above the disc and about 0.2 mm wide. The excipulum and hypothecium are carbonized, and the epihymenium is brownish. The hamathecium is not inspersed and contains anastomosing paraphysoids 1–1.5 μm wide. Ascospores are produced eight per ascus. They are hyaline, narrowly club-shaped, 5–7-septate, and measure 33–37 × 4.5–5.5 μm, without any surrounding gelatinous sheath. Pycnidia (asexual fruiting bodies) have not been observed. In standard spot tests the thallus is UV–, C–, K–, KC– and P–. Thin-layer chromatography has not detected any distinctive secondary metabolites.^[2]

Cresponea pallidosorediata grows on tree bark in semi-deciduous subtropical forest in Parque Pampa del Indio (Chaco Province, northern Argentina) at about 110 m (360 ft) elevation. As of its original publication, it had not been reported from outside Argentina. The type locality lies close to the border with Brazil.^[2]