Lepraria incana

Lepraria incana is a species of dust lichen in the family Stereocaulaceae. First described scientifically by Johann Jacob Dillenius in 1741, and then formally by Carl Linnaeus in 1753, it is the type species of the genus Lepraria. The thallus of this species is green to greyish-green, and powdery – as if made of tiny granules. These granules are soredia, which are asexual reproductive structures. Like most members of genus Lepraria, the lichen has few distinguishing features, lacking both a medulla and sexual reproductive structures (apothecia). Chemically, the lichen is characterised by the presence of the secondary chemicals known as divaricatic acid and zeorin. The lichen prefers to grow on bark on the base of trees in moist and partly shaded locations, but will also grow on dead wood, silica-rich rocks, or soil. It is not particularly selective in terms of its bark substrate, and has been recorded growing on a wide variety of both deciduous and coniferous trees. Lepraria incana is......read more on Wikipedia.