Gyalectidium flabellatum
Gyalectidium flabellatum is a species of lichen-forming fungus in the family Gomphillaceae. It is a leaf-dwelling lichen known from Papua New Guinea and Queensland, Australia, where it grows in lowland to montane forests. The species is distinguished by its characteristic fan-shaped reproductive structures that are broadest around the middle rather than at the base, a feature that separates it from other members of the genus with similarly crystalline thalli.
Taxonomy
Gyalectidium flabellatum was described as a new species in 2001 by Emmanuël Sérusiaux. The type was collected from the south side of Ramu River in Brahman Mission, at an elevation of 100 m. It is distinguished by the characteristic form of its : when well developed, the scales are and typically reach their greatest breadth around the middle rather than at the base.Description
The thallus forms patches about 1–3 mm across that are angular-rounded to almost -. The thallus is composed of small, blister-like segments and is heavily covered with a continuous layer of crystals, giving it a silvery to whitish-grey appearance. Thin greenish thallus parts may be present at the edges.Hyphophores occur at the thallus edges or close to it. Their scales are well developed but can be difficult to see, emerging from a low bulge and lying horizontally. The scales are broadly fan-shaped and have a slightly dentate upper margin. They are typically broadest around mid-height, and measure about 0.1–0.2 mm long and 0.2–0.3 mm broad. Its colour is whitish translucent to bluish grey. Apothecia are angular-rounded, about 0.2–0.3 mm in diameter, with a pale yellowish-brown to greyish that can be thinly pruinose, and a prominent whitish margin. Ascospores are ellipsoid, with dimensions of 30–45 × 10–17 μm. Pycnidia were not reported.