Gyalectidium verruculosum
Gyalectidium verruculosum is a species of lichen-forming fungus in the family Gomphillaceae. It is a leaf-dwelling lichen known from Australasia and the western Pacific, including Papua New Guinea, Australia, and Vanuatu. The species is distinguished by its triangular reproductive scales that typically develop from the inner side of a crescent-shaped crystalline bulge on the thallus surface, a feature that separates it from the externally similar Gyalectidium filicinum.
Taxonomy
Gyalectidium verruculosum was described as a new species in 2001 by Emmanuël Sérusiaux. It was separated from the externally similar Gyalectidium filicinum by the form of its, whose triangular scale typically develops from the inner side of a crescent-shaped crystalline bulge on the thallus surface. The author noted that the species had probably been overlooked in Australasia because it could be confused with G. filicinum.Description
The thallus forms rounded patches about 2–5 mm in diameter. It is finely and pale greenish to greyish in colour.Hyphophores are produced on the thallus surface. Their scales are well developed and usually arise from a crescent-shaped, whitish crystalline bulge. The scales are obliquely to almost horizontally oriented and triangular, measuring about 0.15–0.25 mm long and 0.1–0.15 mm broad at the base. They are whitish translucent to pale greyish, only rarely with a bluish tinge. Apothecia are rare overall but can be numerous on some thalli. When present, they are angular to rounded, about 0.15–0.25 mm in diameter, with a pale yellowish-brown to greenish-grey that may be slightly, and a whitish margin. The ascospores are ellipsoid with dimensions of 25–35 × 10–15 μm. Pycnidia were not reported.