Nick Upton / Garden chair well covered with extensive growths of lichen, including filamentous forms (Usnea sp.), (Evernia prunastri) and Foliose (Flavoparmelia caperata), Cornwall, UK, August.

Bruno D'Amicis / Detail of centuries-old Beech tree (Fagus sylvatica) covered in lichens and mosses. Val Cervara old-growth beech forest. Europe's oldest beech forest. Abruzzo, Lazio and Molise National Park / Par...

Staffan Widstrand / Wild Wonders of China / Temperate cloud forest with tree with Usnea lichen, near the glacier lake at Mount Bawu Bameng, in the Meili Snow Mountain National park, Yunnan, China.October 2017.

Staffan Widstrand / Wild Wonders of China / Temperate cloud forest with Usnea lichens hanging from trees.N ear the glacier lake at Mount Bawu Bameng, in the Meili Snow Mountain National park, Yunnan, China. October 2017.

Staffan Widstrand / Wild Wonders of China / Temperate cloud forest with Usnea lichens hanging from trees.N ear the glacier lake at Mount Bawu Bameng, in the Meili Snow Mountain National park, Yunnan, China. October 2017.

Staffan Widstrand / Wild Wonders of China / Temperate cloud forest with Usnea lichens hanging from trees, near the glacier lake at Mount Bawu Bameng, Meili Snow Mountain National park, Yunnan, China. October 2017.

Staffan Widstrand / Wild Wonders of China / Lichen covered (Usnea longissima) and lichen hanging from the trees in temperate cloud forest, in the Meili Snow Mountain National park, Yunnan China. October

Staffan Widstrand / Wild Wonders of China / Lichen (Usnea Longissima) covered trees in temperate cloud forest, in the Meili Snow Mountain National park, Yunnan China. October

Staffan Widstrand / Wild Wonders of China / Lichen covered (Usnea Longissima) and lichen hanging from the trees in temperate cloud forest, in the Meili Snow Mountain National park, Yunnan China. October

Staffan Widstrand / Wild Wonders of China / Temperate cloud forest with Usnea lichens hanging from trees.N ear the glacier lake at Mount Bawu Bameng, in the Meili Snow Mountain National park, Yunnan, China. October 2017.

Staffan Widstrand / Wild Wonders of China / Lichen (Usnea Longissima) covered trees in temperate cloud forest, in the Meili Snow Mountain National park, Yunnan China. October 2017.

Staffan Widstrand / Wild Wonders of China / Temperate cloud forest with Lichen (Usnea longissima) near the glacier lake at Mount Bawu Bameng, in the Meili Snow Mountain National park, Yunnan China. October 2017.

Staffan Widstrand / Wild Wonders of China / Temperate cloud forest with lichen (Usnea longissima) hanging from tree, near the glacier lake at Mount Bawu Bameng, in the Meili Snow Mountain National park, Yunnan, China. October.

Staffan Widstrand / Wild Wonders of China / Wild Wonders of China. team holding up their flag in the lichen-covered (Usnea longissima) temperate cloud forest, in the Meili Snow Mountain National park, Yunnan China. October

Staffan Widstrand / Wild Wonders of China / Lichen (Usnea longissima) and other plants on tree trunk in cloud forest , near the glacier lake at Mount Bawu Bameng, Meili Snow Mountain National park, Yunnan China. October.

Staffan Widstrand / Wild Wonders of China / Lichen (Usnea longissima) hanging from a tree. Temperate cloud forest sceneries, near the glacier lake at Mount Bawu Bameng, in the Meili Snow Mountain National park, Yunnan, China. October 2017.

Felis Images / Sikkim spruce (Picea spinulosa) branches with male (purple) and female (orange) cones covered in Usnea lichen. Lava, Bhutan.

Felis Images / Sikkim spruce (Picea spinulosa) branches with male (purple) and female (orange) cones covered in Usnea lichen. Lava, Bhutan.

Adrian Davies / Lichen (Usnea florida) Snowdonia, North Wales, October.

Adrian Davies / Lichen (Usnea florida) Snowdonia, North Wales, October.

Adrian Davies / Lichen (Usnea florida) Snowdonia, North Wales, October.

Ingo Arndt / Primary or old growth rainforest with dead tree covered with Beard lichen (Usnea) Arfak Mountains, West Papua, Indonesia.

Solvin Zankl / Lichen (Usnea dasypoga) on English oak tree (Quercus robur) near Norra Kvill National Park, Rumskulla socken, Smaland, Sweden, August.

Solvin Zankl / Lichens (Usnea filipendula, Evernia prunasti, Bryoria fuscescens, Hypogymnia physodes and Parmelia sulcata) on English oak tree (Quercus robur) near Norra Kvill National Park, Smaland, Sweden, August.

Solvin Zankl / Lichen (Usnea dasypoga) on English oak tree (Quercus robur) near Norra Kvill National Park in Rumskulla socken, Smaland, Sweden

Ole Jorgen Liodden / Chimango caracara (Phalcoboenus chimango temucoensis) perched on branch with Usnea lichen. Ushuaia, Argentina, February.

Dong Lei / Forest with trees covered in Old man's beard (Usnea) and Rhododendron flowers (Rhododendron sp) Lijiang Laojunshan National Park, Yunnan Province, China. April.

Axel Gebauer / Coal tit (Parus ater) on branch with Old man's beard lichen (Usnea) Djuga, Kavkazsky Zapovednik, west Caucasus Mountains, Adygea, Russia, March.

Dong Lei / Crested tit warbler (Leptopoecile elegans) on Old mans beard lichen (Usnea sp) Ruoergai National Nature Reserve, Sichuan Province, China, October.

Loic Poidevin / Old man's beard lichen (Usnea longissima), Khutzeymateen Grizzly Bear Sanctuary, British Columbia, Canada, June.

Thomas Marent / Beard Lichen (Usnea sp), Switzerland

Dr. Axel Gebauer / Beard lichen (Usnea), Gonggai Shan Nature Reserve, Kangding / Dartsedo, Tibet, China, August.

XI ZHINONG / Old Man's beard lichen (Usnea longissima) food of Yunnan snub-nosed monkey (Rhinopithecus bieti), Baimaxueshan Nature reserve, Yunnan, China, November

Nick Upton / Garden chair well covered with extensive growths of lichens including Oakmoss (Evernia prunastri) filmanetous forms (Usnea esperantiana and other Usnea spp) and a foliose lichen (Flavoparmelia caperat...

Alex Hyde / Old man's beard Lichen (Usnea sp) growing on tree trunk in coniferous woodland in Aosta Valley, Monte Rosa Massif, Pennine Alps, Italy. July.

Alex Hyde / Bearded Lichen (Usnea sp.) growing on a Scots Pine (Pinus sylvestris). Fasnakyle Forest, Glen Affric, Caledonian Forest Reserve, Scotland, November.

Nature Production / Beard Moss (Usnea longissima) covering trees, Mt. Nyukasa, Nagano, Japan, September

Luciano Candisani / Beard Lichen (Usnea sp), Serra de Bocaina, Brazil

Adrian Davies / Beard Lichen (Usnea subfloridana) a good indicator of clean air, UK

Robert Thompson / Old man's beard lichen {Usnea cornuta} Killary Bay Little, County Mayo, Republic of Ireland, February

Robert Thompson / Old man's beard lichen {Usnea cornuta} Crom Estate, County Fermanagh, Northern Ireland, UK, March

Angelo Gandolfi / Chamois (Rupicapra rupicapra) feeding on Old Man's Beard lichens (Usnea sp) during a harsh winter, Abruzzo National Park, Italy.

Angelo Gandolfi / Chamois (Rupicapra rupicapra), watched by another, feeding on Old Man's Beard lichens (Usnea sp) during a harsh winter, Gran Paradiso NP, Alps, Italy.

Matthew Maran / Western hemlock (Tsuga heterophylla) tree trunk with Blood spattered beard lichen (Usnea wirthii) growing on it, Wild Pacific Trail, Vancouver Island, Canada

Matthew Maran / Western hemlock (Tsuga heterophylla) tree trunk with Blood spattered beard lichen (Usnea wirthii) growing on it, Wild Pacific Trail, Vancouver Island, Canada

Wild Wonders of Europe / Widstrand / Lichen {Usnea filipendula} on a Spruce (Picea abies) Oulanka, Finland, September 2008

Wild Wonders of Europe / Widstrand / Lichen {Usnea filipendula} on a Spruce (Picea abies) Oulanka, Finland, September 2008

Wild Wonders of Europe / Widstrand / Lichen {Usnea filipendula} on a Spruce (Picea abies) Oulanka, Finland, September 2008

Wild Wonders of Europe / Widstrand / Lichen {Usnea filipendula} on a Spruce (Picea abies) Oulanka, Finland, September 2008

Wild Wonders of Europe / Widstrand / Lichen {Usnea filipendula} hanging from Spruce (Picea abies) Oulanka, Finland, September 2008

Ross Hoddinott / Lichen {Usnea ceratina} and {Parmelia sulcata} Devon, UK. October

Flip de Nooyer / Old man's beard lichen {Usnea sp} growing on pine tree, Netherlands

Duncan Mcewan / Lichen {Usnea florida} with apothecia on oak tree bark {Quercus sp}. Scotland, UK

Duncan Mcewan / Lichen {Usnea sp} and {Parmelia sp} on birch bark {Betula sp} Scotland, UK Inverness-shire

Duncan Mcewan / Lichen {Usnea sp} on bark of Birch tree {Betula sp} Scotland, UK Inverness-shire

Duncan Mcewan / Lichen {Usnea sp} on bark of Birch tree {Betula sp} Scotland, UK Inverness-shire

Philippe Clement / Old Man's Beard {Usnea longissima} hanging from the branches of Western red cedar {Thuja plicata}, Glacier NP, Montana, USA

Colin Monteath / Beard Lichen (Usnea sp) in Beech tree branches on Mt Owen Track, Kahurangi National Park, New Zealand

Michael & Patricia Fogden / Lichen Katydid (Markia hystrix) disguised on Beard Lichen (Usnea sp) on which it feeds, cloud forest, Costa Rica

Niall Benvie / Silver birch {Betula verrucosa} with {Usnea sp} lichen on branches, Highlands, Scotland, UK

Niall Benvie / Old man's beard lichen on tree trunk {Usnea sp} Highlands, Scotland, UK

Nature Production / Lichen Katydid {Markia hystrix} camouflaged amongst Beard moss {Usnea sp} Ecuador

David Tipling / Downy birch trees (Betula pubescens) festooned with Old Mans beard lichens (Usnea sp.), Glen Affric, Scottish Highlands, UK. May.

David Tipling / Downy birch trees (Betula pubescens) festooned with Old Mans beard lichens (Usnea sp.), Glen Affric, Scottish Highlands, UK. May.

Will Watson / Grey sallow (Salix cinerea) branches covered by Beard lichen (Usnea sp.), Lochan, Darnaway Estate, Highlands, Scotland, UK. May.

Robert Thompson / Beard lichen (Usnea cornuta) growing on a tree branch, Ards Forest Park, County Donegal, Republic of Ireland. October.

George Sanker / Red-breasted Nuthatch (Sitta canadensis) on a Paper Birch (Betula papyrifera) branch, near hanging Beard Lichen (Usnea trichodea). Acadia National Park, Maine, USA.