Parmelia marmariza

Parmelia marmariza forms firm, closely attached thalli on bark, typically 8–12 cm across, coloured whitish to greenish mineral grey. Lobes are somewhat linear to somewhat lobate, 2–8 mm wide, overlapping and sometimes short, with a smooth to faintly wrinkled upper surface that is shiny and continuous. The margins are conspicuously black-rimmed, and the upper cortex bears numerous raised pale pores (pseudocyphellae) that are 0.2–0.5 mm long, occurring both on the lobe margins and surfaces, often merging to form a network of ridges.^[2]

The lower surface is black and densely covered with rhizines that are simple to forked, 1–2 mm long. Pycnidia are common, producing cylindrical conidia 6–8 micrometres (μm) long. Apothecia (fruiting bodies) are somewhat sessile and 5–12 mm in diameter, with a dark brown disc that becomes flat and split with age; the thalline margin is wrinkled (rugose) and marked by pseudocyphellae. The hymenium is 55–60 μm tall, and ascospores measure 8–9 × 12–14 μm, with a wall about 1 μm thick.^[2]

Chemically, P. marmariza contains atranorin, chloroatranorin, salazinic acid, and consalazinic acid. The species is distinguished from related Asian Parmelia species by its dense, small pseudocyphellae and relatively thick, rugose thalline margins.^[2]

Parmelia marmariza is an Asian species that grows on tree bark in humid temperate to subtropical forests. It is widespread in Japan, where it occurs in several provinces, and is also found in Taiwan and Nepal. Reports from Anhui and Shaanxi provinces in China confirm its broader East Asian range.^[2]

The species is most common in areas with high rainfall and moderate temperatures, often in coastal or montane environments where humidity remains steady throughout the year. It typically colonises smooth-barked trees and occasionally other woody substrates. Specimens from different parts of its range show minor variation in the density of pseudocyphellae and spore size, likely reflecting environmental influences rather than taxonomic differences.^[2]