| Lepraria incana | |
|---|---|
| |
| Lepraria incana on the base of a tree trunk – a favoured habitat | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Lecanorales |
| Family: | Stereocaulaceae |
| Genus: | Lepraria |
| Species: | L. incana
|
| Binomial name | |
| Lepraria incana | |
| Synonyms[1] | |
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 common and widespread in Europe and Asia. Although it was previously thought to be even more widely distributed, with records from North America and South America, research has shown that at least some of the Lepraria incana lookalikes on those continents – although morphologically indistinguishable – are genetically distinct, and they have been described as unique species. Lepraria incana is relatively tolerant to air pollution and some studies have investigated its use as a biomonitor. The lichen is known to harbour several species of lichenicolous fungi as well as a mycovirus.