Parmelia meiophora
Parmelia meiophora is a species of corticolous foliose lichen in the family Parmeliaceae. Described from collections made in Yunnan, China in 1889, this lichen is known only from high-elevation cloud forests in southwestern China, where it grows on tree bark at elevations of roughly 3,000–4,000 metres. The species forms loosely attached, greenish-grey rosette-shaped growths 8–15 cm across, characterized by a shiny surface covered with numerous tiny projections and very small pale pores. It is distinguished by its strongly branched root-like structures on the black undersurface and its chemistry, which produces distinctive colour reactions when tested with potassium hydroxide solution: the turns weakly yellow while the interior changes from yellow to red.
Taxonomy
Parmelia meiophora was introduced as a new species by William Nylander in Auguste-Marie Hue's 1889 work "Lichenes yunnanenses", based on bark-dwelling material from montane forests in Yunnan, China. The protologue cites collections made on 6 and 17 June 1887 above Dapingzi and Mosoying at about 3,000 m elevation. Nylander associated the species with the P. perlata group and recorded its reactions: potassium hydroxide solution tinges the cortex weakly yellow and quickly turns the medulla from yellow to red; the hymenial iodine reaction is blue, later violet. He described brown apothecia that are cup-shaped when young then flatten and noted eight ellipsoid to roughly spherical spores per ascus. A variety proposed by Ji-Ding Zhao in 1964, Parmelia meiophora var. isidiata, is considered synonymous with the nominate variety.Description
Parmelia meiophora forms a loosely attached, firm foliose thallus on bark, coloured greenish mineral grey and 8–15 cm across. Lobes are somewhat irregular, closely contiguous to overlapping, 3–5 mm wide. The upper surface is shiny and flat, becoming finely cracked with age, and carries numerous very small pale pores 0.2–0.3 mm long. The thallus is distinctly isidiate: the isidia are short, wart-like, about 0.1 mm thick and 0.1–0.2 mm tall, unbranched, and their tips often darken. The underside is black and densely rhizinate; the rhizines are plentiful and strongly branched, 1–2 mm long.Fruiting bodies are rare. Apothecia, when present, are and 3–5 mm in diameter; the hymenium is 55–60 micrometres tall and ascospores measure 5–6 × 7–8 μm with an about 1 μm thick. Pycnidia have not been seen. Chemically, the species contains atranorin, salazinic acid, and consalazinic acid.