Peltigera montis-wilhelmii

Peltigera montis-wilhelmii is a rare species of corticolous (bark-dwelling), foliose lichen in the family Peltigeraceae. Found in Papua New Guinea, it was formally described as a new species in 2009 by Emmanuël Sérusiaux, Bernard Goffinet, Jolanta Miądlikowska, and Orvo Vitikainen. The type specimen was collected from Pindaunde valley on Mount Wilhelm (Chimbu Province) at an altitude of 3600 m. The species epithet refers to the type locality.

Description
The lichen has circular that are 5 – across with rounded  up to 4 mm wide. The upper surface is smooth and shiny with an orange-chamois to brownish colour, while the lower surface is whitish to pale orange-brown. The lichen has abundant rhizines that are typically fasciculate and apothecia, which are few but present on almost all thalli examined, are typically horizontal with reddish-brown. The are  to  and have rounded ends, typically have 3 septa (sometimes up to five), and measure 50–61 by 4–5 μm. were not seen in this species. No lichen products were detected using thin-layer chromatography.

Habitat and distribution
Peltigera montis-wilhelmii is a rare lichen that has only been found in the Mt. Wilhelm area. It typically grows on branches in the upper montane forest zone and on the trunk of tree ferns in the subalpine forest, at elevations ranging from 2800 to 3600 m.