Graphis taneina
Graphis taneina is a species of script lichen in the family Graphidaceae. It forms a thin, pale greenish-grey crust on tree bark and produces both powdery patches and elongated, slit-like fruiting bodies. The species is known from the Angkor temple complex in Cambodia, where it grows on various trees in well-lit sites.
Taxonomy
Graphis taneina was described as a new species in 2011 by Minoru Nakanishi, Hiroyuki Kashiwadani, and Kwang Hee Moon from material collected on tree bark near the Ta Nei stone temple in the Angkor area of Siem Reap Province, Cambodia. The holotype is housed in the herbarium of the National Museum of Nature and Science.The authors distinguished the species from similar members of Graphis by a combination of morphology and chemistry: the thallus produces, the are and usually lack obvious striations, the is near the top, and the colourless ascospores have 6–8 transverse septa and measure 30–32 × 7–8 micrometres. It contains 2-methoxypsoromic acid, which helps separate it from lookalikes such as G. bulacana and G. glaucescens, and from G. supracola.
Description
The thallus of Graphis taneina is corticolous, pale greenish-grey to whitish-grey, thin, and lacks a distinct outer. It is partly, forming soralia that are hemispherical to irregular in shape and about 40–100 μm across.The fruiting bodies are to sparingly branched lirellae up to 4 mm long and 0.18–0.3 mm wide. They are erumpent from the thallus and are largely bordered by a almost to the top. The are entire to occasionally grooved, and they are covered with white . Internally, the exciple is carbonised near the top, the hymenium is clear and iodine-negative, and the asci contain eight spores. The colourless ascospores are 6–8-septate and stain purple with iodine, measuring 30–32 × 7–8 μm. The lichen contains 2-methoxypsoromic acid, a rare secondary metabolite in the genus Graphis.