Graphis halonata

Graphis halonata is a species of in the family Graphidaceae, first described in 2018. It is found in Brazil. The species is distinguished by its (rock-dwelling) habitat, presence of, and unique  characteristics.

Taxonomy
Graphis halonata was formally described by the lichenologists Klaus Kalb and André Aptroot in 2018. The type specimen was collected in the Serra do Espinhaco, specifically Serra do Caraça, Bocaina, Minas Gerais, Brazil, on a sandstone boulder at an altitude of 1450 m. The specific epithet halonata refers to the characteristic (halo-like)  found in this species.

Description
The thallus of Graphis halonata is, , discontinuous and uneven. It lacks a, is dull and ochraceous white, measuring up to 0.2 mm thick, and is not surrounded by a. The is. are erumpent from the thallus, completely, not striate, wavy linear, irregularly branched and partly divided into separate discs, measuring 0.5–2.5 mm long, about 0.4 mm wide, and approximately 0.3 mm high. The rim is black, and the is lateral and ochraceous white. The is 100–125 μm high and not. , which number eight per, are hyaline, IKI+ (violet), and broadly ellipsoid in shape. These spores are (i.e., divided into  or locules by intersecting 3–5 longitudinal and 0–3 transverse septa), measuring 18–26 by 12–15 μm, surrounded by a gelatinous sheath about 5 μm wide, with lumina arranged somewhat spirally. were not observed.

Chemical spot tests show that the thallus and thalline margin of the are UV−, C−, P−, and K+ (yellow turning red). Thin-layer chromatography analysis shows the presence of norstictic and connorstictic acids.

Habitat and distribution
Graphis halonata was found on a free-standing sandstone boulder and at the time of original publication was known only from Brazil.