Pyxine glaucescens
Pyxine glaucescens is a species of foliose lichen in the family Caliciaceae. It was first described from Comiran, where it grows on the bark of broad-leaved trees. The lichen forms a thin, leaf-like thallus with a bluish-grey upper surface and a blackish underside anchored by short root-like structures. Its small, round, black fruiting bodies produce brownish ascospores.
Taxonomy
Pyxine glaucescens was first described by the Finnish lichenologist Edvard August Vainio in 1913. Vainio noted that it resembles Pyxine retirugella in overall habit, but differs in the colour and KOH reactions of both the and the.Description
Pyxine glaucescens is a foliose lichen. The thallus is fairly thin, glaucous on the upper surface and , opaque, and without soredia or isidia. The medulla is white. In simple spot tests the upper surface is K−, while the interior turns yellowish then reddish. are about 0.5–1 mm wide, irregular and somewhat confluent, contiguous and plane, with a slightly -wrinkled surface. The thallus underside is blackish with short blackish rhizines.The fruiting bodies are 0.7–1.2 mm across, in form with a black margin; the is flat, black and naked. The outer is aeruginous-sooty and K+ ; inside it is dingy whitish. The is whitish below and brownish above, K+, and the is aeruginous-sooty and K+. Ascospores number eight per ascus, arranged in two rows, brownish and oblong with obtuse tips, 1-septate, with an unevenly thickened wall ; they measure 17–22 μm × 5–8 μm.