Chris Mattison / Cumberland rock-shield lichen (Xanthoparmelia cumberlandia) with numerous apothecia. San Diego, California, May.

Nick Upton / Lungwort / Green satin lichen (Lobaria virens) with apothecia fruiting bodies on a treetrunk in ancient Atlantic woodland, Knapdale Forest, Argyll, Scotland, UK, May.

Nick Upton / Lungwort / Green satin lichen (Lobaria virens) with apothecia fruiting bodies on a treetrunk in ancient Atlantic woodland, Knapdale Forest, Argyll, Scotland, UK, May.

Alex Hyde / Lichen (Lobaria virens) with mature apothecia (or fruiting body) growing on a sycamore tree trunk. Isle of Mull, Scotland, UK. June.

Alex Hyde / Lichen (Lobaria virens) with mature apothecia (or fruiting bodies) growing on a sycamore tree trunk. Isle of Mull, Scotland, UK. June.

Alex Hyde / Lichen (Lobaria virens) with mature apothecia (or fruiting body) growing on a sycamore tree trunk. Isle of Mull, Scotland, UK. June.

Chris Mattison / Cup lichen (Cladonia diversa) showing red apothecia. Derbyshire, England, UK, September

Nick Upton / Common orange lichen (Xanthoria parietina) with many cup-shaped apothecia fruiting bodies, growing on Hawthorn branch (Crataegus monogyna) in early spring, Wiltshire, UK, March.

Alex Hyde / Lichen (Xanthoria parietina) found growing on a twig, showing mass of apothecia (cup-shaped fruiting bodies). This species is very resistant to air pollution. Peak District National Park, UK, January.

Alex Hyde / Lichen (Xanthoria parietina) found growing on a twig, showing mass of apothecia (cup-shaped fruiting bodies). Peak District National Park, UK. January.

Alex Hyde / Lichen (Cladonia diversa) showing red apothecia (spore-producing structures). Cairngorms National Park, Grampian Mountains, Scotland, UK, February.

Adrian Davies / Dog Lichen (Peltigera sp.) growing on oak bark. Note reddish spore producing apothecia. The Trossachs, Scotland, February.

Alan Watson / Insect amongst apothecia of Lungwort (Lobaria virens), on Oak tree (Quercus petraea) temperate forest, Tomies Wood, Killarney National Park, County Kerry, Republic of Ireland, Europe

Alan Watson / Toadstool growing amongst apothecia of Lungwort (Lobaria virens), on Oak tree (Quercus petraea) temperate orest, Tomies Wood, Killarney National Park, County Kerry, Republic of Ireland, Europe

Alan Watson / Lungwort (Lobaria virens) with apothecia visible, on an Oak tree (Quercus petraea), temperate forest, Tomies Wood, Killarney National Park, County Kerry, Republic of Ireland, Europe

Alan Watson / Detail of Dog lichen (Peltigera polydactylon), showing fruiting body (apothecia), in temperate rainforest, Upper Incomappleux Valley, British Columbia, Canada.

Duncan Mcewan / Crustaceous lichens {Apothecia, Rhizocarpon geographicum}, moorland rock, Inverness-shire

Duncan Mcewan / Crustaceous lichen {Lecidea dicksonii} with apothecia on rock. Scotland, UK

Duncan Mcewan / Lichen {Icmadophila ericetorum} with apothecia on peaty soil Scotland, UK Inverness-shire

Duncan Mcewan / Lichen {Icmadophila ericetorum} with apothecia on peaty soil Scotland, UK Inverness-shire

Duncan Mcewan / Lichen {Lobaria laetivirens} with apothecia on tree bark Scotland, UK Inverness-shire

Duncan Mcewan / Cudbear lichen {Ochrolechia tartarea} with apothecia on tree base. Scotland, UK

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

Duncan Mcewan / Lichen with fruiting apothecia on rock {Haematomma ventosum} Scotland, UK

Will Watson / Crustose lichens on Silurian limestone stone wall with Black apothecia (Tephromela atra), Lecanora rupicola and Ochrolechia parella, Bradnor Hill, Herefordshire, England, November, focus stacked.

Adrian Davies / Tree lungwort (Lobariella pseudocrenulata) with apothecia fruiting bodies. Savegre Valley, Costa Rica.