#LichensGBI

Classic lichen assemblage on High Weald worked wood (gate). West Sussex. Hypogymnia physodes, Flavoparmelia soredians, Cladonia polydactyla. #LichensGBI

Glimpse of sun at Achahoish

Cetrelia olivetorum with tiny white freckles on the upper surface

Leptogium cyanescens, thin with pale grey with small frills turning into lobelets on the lobe margins

Pannaria rubiginosa, fairly common with orange-brown fruit and small lobes with pale margins.

We're in Knapdale for the week to explore the scattered oceanic woodlands and coastal rocks for lichens, starting with Cetrelia olivetorum, Leptogium cyanescens and Pannaria rubiginosa. #LichensGBI

Varicellaria hemisphaerica and Punctelia jeckeri on dying Ash, Fraxinus excelsior. A stand edge veteran Ash in open ancient woodland. North of Cowfold. Low Weald. #LichensGBI

There are stripes of the lichen Lecanactis abietina on nearly every Quercus robur in Costells Wood, Scaynes Hill. Low Weald ancient woodland. This is a common occurrence in most low and high weald woodland. #LichensGBI

Pedunculate Oak covered in Usnea cornuta. Costells Wood. Scaynes Hill. Low Weald ancient woodland. Usnea spp. are not that common in Sussex; although U. cornuta is the most common of those we have. Typically, you saw a small clump; it is rare to find a trunk covered in it. #LichensGBI

This fabulous cluster of ancient Fagus sylvatica in the hollow-way to Diddling Village were barely standing up as the soil around their roots had been eroded. At first sight, few lichen in the dark way. But look carefully and there was plenty of Enterographa crassa & Graphis scripta s.l. #LichensGBI

Pleased to see lots of Cresponea premnea on ancient Quercus robur in Didling Churchyard. Part of Lecanactidetum premneae community. Seen C. premnea in High Weald in Sussex, but never in Low Weald. Growing with Dendrographa decolorans; also a dry oak lichen. @britishlichensociety.org.uk #LichensGBI

Visited the 500+ year old Yews at Kingley Vale NNR, W. Sussex. Apart from Lepraria sp. there were very view lichens on them. Like ancient churchard yews, a few had Opegrapha vermicellifera on decorticated areas of their trunks. But no Zwackhia prosodea as on some ancient churchard yews #lichensGBI

Close-up of the lichen Cladonia coniocrea. This photo shows the lichen's podetia, its spore-forming structures, that are a few cm high with pointy ends. Strung between them is the remains of a spider web. They are growing on a 250 year old sandstone gravestone in mid Sussex. To the left is a moss and to the top right is the light-green foliose lichen Flavoparmelia caperata.

On a 250 year old gravestone in Sussex - Cladonia coniocrea - perfectly capturing a mood #lichensGBI

Observing heathland lichens with members of Suffolk Naturalists' Society at Westleton Common, Westleton, Suffolk, England. Image courtesy of Joan Hardingham/Suffolk Naturalists' Society.

Leading public lichen walk for Halesworth Area Sustainability Hub at Rydal Mount, Wissett, Suffolk, England. Image courtesy of Rachel Kellett/Halesworth Area Sustainability Hub.

Greatly enjoyed leading two #lichen events in Suffolk this past weekend! Saturday: observing heathland lichens at Westleton Common with @suffolk-nats1929.bsky.social. Sunday: taking public on a lichen walk for Halesworth Area Sustainability Hub in Wissett. @britishlichensociety.org.uk #lichensGBI

St. Margaret's Rottingdean. With chest tombs U don't need to bend down to ID! Bagliettoa calciseda, Circinaria calcarea, Variospora flavescens, Lecidella stigmatea, Kuettlingeria teicholyta, Gyalolechia flavovirescens, Catillaria lenticularis, Verrucaria nigrescens, Variospora flavescens #LichensGBI

An old wooden fence in the process of being reduced

5 pieces of wood with crustose lichens growing on them. Don't you just love it when you can take the piece of wood instead of having to try and cut a sample off!

A light brown crustose lichen with a 10 cm ruler in the photo for scale. The thallus is about 20cm by 5cm in size

A close up of the thallus showing several squamules (small scales) with white powdery edges, which are soredia. The red scale bar is 1mm. Larger squamules about 1.5mm but many much smaller.

We recently removed some of an old (pine) fence and as well as gaining some firewood, I acquired plenty of lichen samples to play with. So far, I have identified 2 of the crustose ones. First up is Hypocenomyce scalaris. No apothecia on my sample but unmistakeable C+red reaction #lichensGBI 1/2

Nice to see a lichen that's not crustose on a church wall. Cladonia pixidata. West wall of Stopham church. West Sussex. UK. See simelliottnaturenotes.blog/2025/06/14/l... for the other I lichens I saw. #LichensGBI

Diploicia canescens. "Black apothecia (<1mm diameter) rare except in the south, particularly near the coast" @britishlichensociety.org.uk Voilà! Rottingdean. Chestnut, on Aesculus hippocastanum. #LichensGBI

On dry ancient oak in Ashburnham Park, E/ Sussex, 7 mile up from coast. First I thought this (photo one 7x & photo two 1x) was Enterographa crassa; then I wondered whether it was Enterographa sorediata, i.e. the sorediate morph of Syncesia myrticola. But now I am not sure what it is? #lichensGBI

2/2 Punctelia subrudecta, Ochrolechia subviridis, Lepra albescens, Haematomma ochroleucum. A symphony in grey. #lichensGBI

Parmotrema crinitum; the Desperate Dan lichen. Distinguished from other Parmotrema species by the ciliate isidia; looking like Desperate Dan's beard hairs. On Quercus petraea. Nettlecombe Park. Pointed by Nicola Bacciu on a @britishlichensociety.org.uk LEAF course. Fabulous course. #LichensGBI

Phlyctis argena : England : VC26 West Suffolk : TM0540 : May 2025 : On Fraxinus trunk : K+ yellow turning red : Pd+ yellow-orange

Phlyctis argena : England : VC26 West Suffolk : TM0540 : May 2025 : On Fraxinus trunk : K+ yellow turning red : Pd+ yellow-orange

Phlyctis argena on ash, Raydon Wood, Suffolk, England. Showing characteristic spot-tests. This pollution-tolerant #lichen is widespread and locally common in Britain. Find it near you! Field notes aspenecology.com/phlyctis-arg... @suffolk-nats1929.bsky.social @britishlichensociety.org.uk #lichensGBI

Thanks for taking part, Tim: it was a brilliant day, and a delight to introduce so many people to the strange, beautiful and ecologically vital world of #lichens! @suffolk-nats1929.bsky.social also helped to fund the workshop, so special thanks to them as well. #lichensGBI

Collema glebulentum in basic flush on Torridonian sandstone

Lepra dactylina on summit of Beinn Alligin, showing yellow K reaction but not K+purple on isidia tips - that would be Pertusaria oculata

Pseudocyphellaria citrina with yellow soredia on willow in sheltered chasm

For invasive species week UK, here we are pulling up Rhodendron ponticum seedlings spreading up a mountain in Torridon. It's National Trust Scotland land but there's a massive seed source below on the Torridon Estate. Selling and planting this horror should be illegal. #invasivespecies #lichensgbi

Cetrariella commixta

Cetrariella commixta: close up

Allantoparmelia alpicola

Cornicularia normoerica

More lichens from Ben Alligin: Cetrariella commixta, Allantoparmelia alpicola and Cornicularia normoerica. 4/n #LichensGBI

Pachyphiale carneola. A classic ancient woodland indicator species, relatively common on Sussex old oaks in ancient woodlands. On Quercus robur in South Downs chalk and clay-with-flints ancient woodland SSSI West Sussex. #LichensGBI @britishlichensociety.org.uk

Pertusaria coccodes. Mostly a south-east species. On Quercus robur in South Downs chalk and clay-with-flints ancient woodland SSSI. K+ yellow turning red. #LichensGBI @britishlichensociety.org.uk

Peased to see
Schizotrema (Schismatomma) quercicola on Quercus robur, in a Chalk & Clay-With-Flints SSSI ancient woodland, Downs, W. Sussex. A west country & south coast species. An NIEC 'old woodland' indicator. As all Schismatomma sp. scratches orange. #LichensGBI @britishlichensociety.org.uk

And even smaller ... Enterographa crassa. Marstakes Common; Low Weald ancientwoodland. Common on ancient broad-leaved trees in the south. Miniscule apothecia dots (0.1mm) in lines. Very hard to notice that this lichen is there; but you can train your eyes 4 the smoother areas of thallus #LichensGBI

Cladonia macilenta or C. floerkeana? These are tricky. On lignum (sawn end of a felled Sweat Chestnut). Thallus K+ yellow, so Macilenta! I think. @rspb.bsky.social Broadwater Warren. Heathland being restored. East Sussex nr. Tunbridge Wells. #LichensGBI

Cladonia digitata & C. fimbriata on dead stool of ancient coppiced Sweet Chestnut, @rspb.bsky.social Broadwater Warren, E. Sussex. Despite Sweet Chestnut being seen as having little ecological value, old dead stools in the High Weald are often good substrates for Pixie Cup Cladonia. #LichensGBI

A lovely ancient Quercus robur in Wadhurst Park; an ancient deer park. Its bark was dominated by Pyrrhospora quernea and Dendrographa decolorans. These lichens are very common on old oaks in the south. #LichensGBI

Lepraria finkii is a very common lichen in Sussex. It doesn't mind what it grows over; here, two pretty rare things: the fern Hymenophyllum tunbrigense and the liverwort Calypogeia integristipula (I think?). On Ardingly Sandrock. High Weald. Sussex. #LichensGBI #bryophytes #liverworts

A hair like lichen growing on the frank of a pine tree.

A tuft of a hair like lichen growing on the bark of a pine tree.

Bryoria fuscescens was a very pleasant surprise when I was recording in a monad a couple of miles from our house.
#lichensgbi