''Ocellularia flavescens'' is a species of corticolous (bark-dwelling)

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Graphidaceae The Graphidaceae are a family of lichens in the order Ostropales. Distribution and ecology The vast majority of Graphidaceae species are restricted to the tropics. Most Graphidaceae species are epiphytic (i.e. they grow only on plants). Gener ...

. Found in northern Thailand, it was formally described as a new species in 2002 by lichenologists Natsurang Homchantara and

Brian J. Coppins Brian John Coppins (born 1949) is a botanist and lichenologist, considered a world authority on crustose lichens and a leading expert on the genus ''Micarea''. Education Coppins' interest in lichens was sparked during a field trip to the Scott ...

. The type specimen was collected from Doi Suthep National Park ( Chiang Mai Province); here it was found in an oak/

chestnut The chestnuts are the deciduous trees and shrubs in the genus ''Castanea'', in the beech family Fagaceae. They are native to temperate regions of the Northern Hemisphere. The name also refers to the edible nuts they produce. The unrelat ...

forest at an elevation of . It is only known from the type collection at the type locality. The lichen has shiny, smooth, whitish to mineral-grey thallus. It contains lichexanthone, a

secondary compound Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the norma ...

that is uncommon in genus ''

Ocellularia ''Ocellularia'' is a genus of lichens in the family Graphidaceae. The genus was circumscribed by Georg Friedrich Wilhelm Meyer in 1825. Species *'' Ocellularia africana'' *'' Ocellularia allosporoides'' *'' Ocellularia andamanica'' *''Ocellul ...

''. The presence of this chemical causes the lichen thallus to fluoresce a golden-yellow colour when lit with a long-wavelength (365 nm)

UV light Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...

. This feature is referenced in its

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''flavescens'' ( Latin for "becoming yellow or golden").

References

flavescens Lichen species Lichens described in 2002 Lichens of Thailand Taxa named by Brian John Coppins Taxa named by Natsurang Homchantara {{Ostropales-stub