Graphis norstictica


Graphis norstictica is a species of script lichen in the family Graphidaceae. It was described as new to science in 2009. This lichen forms pale greyish patches on tree bark with elongated, branched fruiting structures that contain a chemical compound called norstictic acid. It has been found in tropical regions including the Philippines, Kenya, and Papua New Guinea, where it grows on the bark of trees.

Taxonomy

Graphis norstictica was described in 2009 by Alan W. Archer and Robert Lücking from a specimen collected in the Philippines and originally associated with the name Graphis nanodes. The original material of G. nanodes comprised two syntypes, one containing norstictic acid and another lacking lichen substances. Since Edvard Vainio's 1921 description of G. nanodes reported the thallus as K−, the chemically negative syntype was designated as the lectotype for that species. The well-developed norstictic acid–containing collection lacked a valid name and was therefore described as G. norstictica; its specific epithet refers to the presence of this lichen product.
The species belongs to a small group of three closely related taxa that share similar morphology and anatomy and similar chemistry but differ in ascospore size.

Description

The thallus of G. norstictica is corticate, smooth to uneven in texture, and white to pale yellowish grey in colour. The —elongated, often branched fruiting bodies typical of Graphis—are, possess a lateral, and are elongate with irregular branching. They measure 1–5 mm long by 0.2–0.3 mm wide, and their edges are entire. The is laterally, and the hymenium is clear, lacking oil droplets or granules. Each ascus contains eight ascospores, which are, colourless, and measure 35–50 × 17–25 micrometres.

Habitat and distribution

Graphis norstictica has been recorded from the Philippines, Kenya, and Papua New Guinea. It occurs in habitats suitable for other lineola-morph Graphis species, typically on the bark of trees in tropical or subtropical regions.