ROSETTE LICHENS : Physcia tenella
This is common and often found on mature trees.
The British Lichen Society tell us that its Thallus are pale grey, seldom more than 5cm diameter. Lobes are long and rather erect, up to 1mm wide with white mottling and prominent marginal cilia. Under surface white with scattered darker-tipped rhizines. The lobe ends split and turn back to expose rather coarse cream coloured soredia. When fertile, apothecia to 2mm diameter on short stalks... hyscia adscendens is similar.
Thallus = the plant body of algae and fungi, and other lower organisms
Lobes = as in foliose lichens are leaflike in appearance
Soredia = soredia serve as agents of vegetative propagation and are seen as a powdery dust on the lichen surface.
Rosette lichen seen growing over moss on a tree in the Vale of Leven Industrial Estaten in November
BRITISH LICHEN SOCIETY : https://britishlichensociety.org.uk/sites/default/files/Physcia%20tenella.pdf
