Psora taurensis

Psora taurensis is a species of terricolous (ground-dwelling), squamulose lichen in the family Lecanoraceae. It is found in the Taurus Mountains of Turkey.

Taxonomy
Psora taurensis was formally described as a new species in 2017 by Ernst Timdal, Mika Bendiksby, Arife Merve Kahraman, and Mehmet Gökhan Halıcı. The type specimen was collected by Halıcı along the Gülnar-Silifke highway (near the exit to Kayrak) (Mersin Province); there, at an altitude between 1000 and 1020 m, the lichen was found growing on soil over calcareous bedrock. The lichen's occurrence in the Taurus Mountains is alluded to in the species epithet taurensis. Molecular phylogenetic analysis shows that Psora tenuifolia is a sister species.

Description
Psora taurensis has a squamulose thallus, with the individual squamules measuring up to 8 mm wide; the thallus develops concave lobes. The upper surface of the thallus is dull and brown, with pruina covering the outer part of the lobes. The lower thallus surface is white to pale brown. Apothecia are brownish-black, convex and lacking a distinct margin, with a diameter of up to 1.5 mm in diameter. The ascospores are ellipsoid and hyaline, measuring 11–16 by 5.5–7 μm.

Psora taurensis contains norstictic acid, a lichen product that can be detected using thin-layer chromatography. This substance is present as crystals in the medulla, along with crystals of calcium oxalate. The expected results of standard chemical spot tests on this species are medulla K+ (yellow turning red), C−, KC−, and P+ (orange).

Habitat and distribution
Known to occur in only two localities in Turkey, Psora taurensis appears to prefer a Mediterranean climate and an elevations of about 1000 m. The habitats at these places are a rocky area with shrubland vegetation in one, and an open pasture in the other.