Upretia squamulosa
Upretia squamulosa is a species of saxicolous, squamulose lichen in the family Teloschistaceae. It was identified as a new species in 2019 from specimens collected in the hot, dry valleys of the Jinsha River system in Yunnan, China, in the hot, dry valleys of the Jinsha River system, at elevations between about 1,240 and 3,160 metres. The lichen forms greyish green to brown scaly growths up to 7 cm across on rock surfaces. It is distinguished chemically by the presence of gyrophoric and lecanoric acids.
Taxonomy
The lichen was scientifically described as a new species in 2019 by Yan Yun Zhang and Li Song Wang. The species epithet refers to its thallus. The type specimen of Upretia squamulosa was collected in Yunnan Province, China, specifically in Huize County, Zhehai Town, at an elevation of.Upretia was proposed as a genus within the subfamily Caloplacoideae of the family Teloschistaceae in 2017. In a 2023 molecular study based on internal transcribed spacer sequences, Upretia was recovered as a strongly supported monophyletic genus, sister to Ioplaca pindarensis. In the same analysis, Upretia squamulosa was represented by multiple Chinese specimens, and a clade of newly collected southwestern Chinese material was recovered as sister to U. squamulosa.
Description
Upretia squamulosa is characterised by its squamulose, thallus that ranges in colour from greyish green to brown. The are convex, sometimes resembling a bullet shape, with their apex often free from the. This species has apothecia, which are pale brown to brown in colour, and ascospores. In cross-section, the apothecia often show an inner proper margin, and the is usually present early but may become less distinct as the apothecia develop. The thallus and apothecia contain gyrophoric and lecanoric acids, but no anthraquinones are found in the apothecia.The thallus of Upretia squamulosa is saxicolous and squamulose, without an margin, and can grow up to in diameter. The upper surface is non-, smooth, and without cracks. The hymenium of the apothecia is colourless and the is pale brown. The species does not form pycnidia.
Upretia squamulosa is similar to Upretia zeorina but differs in having greyish green to brown, non-pruinose, imbricate squamules and generally larger apothecia with a pale brown to brown disc; it also produces lecanoric acid in addition to gyrophoric acid.