Upretia zeorina
Upretia zeorina is a species of crustose lichen in the family Teloschistaceae. It forms small, dark brown to blackish scaly patches on exposed rock in the hot, dry valleys of the Jinsha River system in Sichuan and Yunnan provinces, at elevations of roughly. The species is distinguished by its black fruiting bodies with a distinctive double-margined structure and a whitish powdery coating on the thallus. Chemically, it contains gyrophoric acid as its sole major secondary metabolite.
Taxonomy
Upretia zeorina was described as a new species in 2023 by Lijuan Li and Christian Printzen, based on material collected from arid-valley localities in southwestern China. In internal transcribed spacer-based phylogenetic analyses, the specimens formed a well-supported lineage within Upretia, recovered as sister to Upretia squamulosa; the genus itself was recovered as monophyletic and sister to Ioplaca pindarensis. The type was collected on rock in Sichuan at about.The epithet zeorina refers to the apothecia, which have a structure with a thalline outer margin and a distinct inner. In the original comparison, U. zeorina was separated from the Indian type species U. amarkantakana by its darker thallus, zeorine apothecia with black, larger ascospores, longer conidia, and the presence of gyrophoric acid. It is also close to U. squamulosa in spore size and overall ecology, but differs in its blackish, partly thallus and black apothecial discs, and in producing gyrophoric acid without lecanoric acid.
Description
The thallus is and to, with an irregular outline. Individual are typically flat and closely attached to the rock, only rarely lifting at the edges, and are about 0.5–2.5 mm across. The upper surface is brown to blackish brown, smooth to faintly cracked, and often has a whitish dusting of, most evident around the margins. Beneath, the thallus lacks rhizines. The medulla is grey, and the is a green alga.The apothecia are zeorine,, and usually numerous, scattered or clustered, up to about 1.2 mm in diameter. The disc is black and ranges from slightly concave to flat; the inner proper margin persists and is typically slightly raised or level with the disc, while the is the same colour as the thallus. Microscopically, the hymenium is iodine-positive, the asci are Teloschistes-type with eight spores, and the hyaline ascospores are and broadly ellipsoid, about 11.5–18.0 × 6.5–11.0 μm. Pycnidia are immersed, producing narrowly bacilliform conidia about 4.0–6.0 × 0.5 μm.
In spot tests, the thallus and thalline apothecial margin are K− but C+. Thin-layer chromatography detected gyrophoric acid as the only major secondary metabolite reported for the species.