Parmeliella testacea

As with other lichens in the Pannariaceae this species with cyanobacteria as the photosynthetic partner usually has a distinctive blue-black rim to the thallus (called the hypothallus). It, however, barely extends out from the edge of the thallus in this species. The centre of the thallus consists of chestnut to grey brown lobes that become quite elongate towards the edge. These squamules break down to initially form similarly coloured knob-like soralia that in turn develop into extensive patches of blue-grey soredia that can cover most of the thallus. When fresh and moist it can be separated from most other species by its distinctive hospital disinfectant smell. P. triptophylla has more elongate isidia and smaller marginal squamules. Fuscopannaria sampaiana has cream-coloured soralia (not blue-green). (RGW)

Photo: Ray Woods