Explainer
The beautiful species thriving on Exmoor - and why it's a good sign
A rare species that is thriving on Exmoor is a positive sign for nature, according to wildlife experts.
The Beard Lichen is highly sensitive to air quality and therefore will only grow in areas with low pollution levels, staff at Exmoor National Park say.
The delicate species, often found anchored onto the bark of tree trunks and branches, is formed from fungi and algae.
Exmoor National Park ranger Charlotte Wray said: "Lichens are a wonderful example of cooperation in nature, as they bring together a plant species with a fungi species.
"The resultant lichens are an endlessly diverse group which occupy many different habitats and have done so for millions of years.
"Being so reliant on good air quality, and being particularly sensitive to sulphur dioxide levels, lichen species are found in areas of low pollution.
"On Exmoor we have many lichen-rich habitats such as the woodland through the Barle Valley, the coastal woodland that stretches from Porlock to Countisbury and the temperate rainforest at Horner Wood which supports many rare important lichens."
Beard Lichens also contain a type of acid which is an antibacterial and antifungal agent.
A Woodland Trust spokesperson said: "It's effective against bacteria including tuberculosis and was traditionally used to treat wounds.
"Native Americans used it as a compress to prevent infection and gangrene.
"It is also said to be edible and contains a high level of vitamin C."
The species can take on a variety of shapes and forms, including:
Bushy beards
Crusty spots
Leafy pads
Small standing branches
Lichens can take a long time to develop, growing only 1-2mm a year.