Gyalectidium novoguineense

The thallus forms minute, dispersed to confluent, irregular patches about 0.3–0.5 mm across, which together can form an aggregate up to about 5 mm across. The thallus is composed of small, blister-like segments (areolate-bullate) covered with crystals that create a silvery to whitish-grey appearance, sometimes with thin greenish zones visible at the margins.^[2]

Hyphophores (structures for asexual reproduction) are produced at the edges of the thallus. Their scales are small, horizontally arranged, and very narrowly triangular, measuring about 0.07–0.15 mm long and 20–50 μm broad at the base. The scales are whitish to pale grey. Apothecia (fruiting bodies) are rare, typically 1 (sometimes up to 3) per thallus patch. They are angular-rounded, about 0.2–0.3 mm in diameter, with a greyish to pale yellowish-brown disc and a slightly prominent whitish margin that typically bears a thin brownish line on its inner edge. The ascospores are ellipsoid to ovoid, measuring 40–50 × 20–30 μm. Pycnidia were not reported.^[2]

Ferraro and colleagues reported Gyalectidium novoguineense from low-elevation sites along the northern coast of Papua New Guinea, and also from south-west Australia and New Caledonia. The collections were from both natural rainforest and artificial habitats (including botanical garden material in Papua New Guinea).^[2] It has also been recorded from Mexico,^[3] and from Thailand.^[4][5]