Bristol Estate, Brighton - Swedish Whitebeam - Physcia clementei and Physcia tribacioides 05.05.2026

Physcia tribacioides and Physcia clementei are rare lichens, found on a Swedish Whitebeam in a social housing estate in Brighton (Bristol Estate)

Physcia tribacioides: ICUN red list status: Vulnerable, thus a section 41 species afforded special protection. British Lichen Society Status: Nationally Scarce

Physcia clementei: ICUN red list status: Near Threatened; British Lichen Society Status: Nationally Scarce

Physcia tribacioides

Physcia clementei: 

For more on these lichens, see: 

Rare and common lichens on urban road trees in the Bristol Estate, East Brighton, and native pre-estate downland Elms. May 2026

Elder and Hawthorn, Lullington Heath National Nature Reserve 14.04.26 Usnea articulata

I had first spotted some Usnea articulata on a Elder on December 3th 2024; and I saw much more on the same tree on February 24th 2026; then on Monday 14th I noticed more U. articulata on a neighbouring Hawthorn. Neither of these trees has significance as a natable, veteran or ancient tree; but the lichen on them - Usnea articulata - is of great significance as U. articulata, is extremely rare in Sussex, and Lullington is at the extreme easterly limit of its distribution. I have informed Nature England of the locations.

Usnea articulata is Near Threatened on the IUCN red list; a Section 41 Species - Priority Actions Needed on the UK Biodiversity Action Plan and an "International Responsibility" lichen. The British Lichen Society (BLS) considers 101 species in the UK to hold an "International Responsibility" status. In some cases, this refers to species that are near extinction globally. The British Lichen Society uses a definition where a species qualifies for IR status if Britain has more than 10% of its European or global population

Elder, Sambucus nigra

Usnea cornuta

The Usnea in the Elder was spread over several twigs and is at the top of the tree, so hard to see.

Hawthorn, Crataegus monogyna

Usnea articulata

This Usnea was at head height in the Hawthorn and was much easier to see.

Distribution of Usnea articulata in UK

From British Lichen Society

Description:

One of the few readily identifiable green/grey beard lichens when well grown. Its straggly, hair-like, tangled, usually unattached stems that can be up to a metre long, swell at intervals along the main branches to create small green/grey sausage-like strings c 3mm in diam. Young material without pronounced swellings could be confused with other species . Usnea articulata | Lichens of Wales

In Sussex, Usnea articulata has been recorded at:

Pagham Church, in 1991

East Dean Park Wood, in 1977 and 1989

West Dean Woods, in 1970, 1986

St Leonards Forest, in 1805

I have seen it at:

- East Dean Park Wood, high up in an Ash on 4th December 2024

and at Devil's Dyke north of Brighton, on a Hawthorn on the South Down's Way.

See my blog for more information: Friston Forest, Lullington Heath NNR and the Cuckmere Valley Churches; abundant Ingaderia vandenboomii (pink powder) and Usnea articulata (strings of sausages) 24.02,26 – Sim's Nature Notes

Craven Vale, Brighton, Sycamore. 27.01.26 Ramalina fraxinea

 

Ramalina fraxinea 

They are only 17 Ramalina fraxinea records in 12 places (all of them rural) in the British Lichen Society database for East and West Sussex,

It is an“International Responsibility” (IR) lichen i.e. a lichen species whose populations in a specific country (e.g. the UK) are internationally significant. Because the national population is so important to the overall survival of the species, the nation has a special responsibility to protect it from extinction or decline.

For more information see: Ramalina fraxinea in a Brighton suburb: under-recording of (urban) Lichens. 27.01.26

 

Lake Wood, Uckfield. Pedunculate OK. 26.01.26

 

Thelotrema lueckingii

Thelotrema lueckingii and Thelotrema lepadinum are closely related, corticolous (bark-dwelling) crustose lichens in the family Graphidaceae. T. lueckingii was relatively recently separated from T. lepadinum based on the consistent presence of yellow pigments in the medulla and within the fertile warts. This paragraph was generated with the assistance of Google Gemini 3 AI

Previously I thought this huge patch of Thelotrema on this Quercus robur was Thelotrema lepadinum but I hadn’t tested it with chemical reagents. Today I tested its thallus with potassium hydroxide; it was dark yellow. T. lepadinum tests negative to potassium hydroxide; but T. leuckingii tests red to potassium hydroxide. This tested dark yellow. So it may be Thelotrema lueckingii?

For more inofrmation see: A liverwort and some lichens in Lake Wood, Uckfield, East Sussex. 26.01.26

Isfield Ancient Hedge, Pedunculate Oak. 19.11.25

Qurcus robur, Pedunculate Oak

Pleurosticta acetabulum 

Found on deciduous trees in well-lit habitats; in the past common, but in the 21st century there have been few record. A very south-east lichen! 

High Weald Medieval Deer Park Lobaria pulmonaria on Ash 14.09.24

I am unable to name the location of this lichen, as the owner of this park does not want any bioologcal observations on his property to be in the public domain,

Once common and widespread, they're now pushed to the westernmost extremities of the UK due to air pollution. Woodland Trust Lungwort Lichens

Ash, Fraxinus excelsior

This Ash is not in good conditions, so this lichen is very vulnarable

Lobaria pulmonaria

This is probably the last Lobaria pulmonaria left in Sussex, but formerly it was not alone. Here is a screen shot of the British Lichen Society database for Sussex's L. pulmonaria listings.

It was recorded at East Dean Park Wood, Parham Park, and St Leonard's Forest as well as this site

In the Atlas of Sussex Mosses, Liverworst and Lichen (1991) Rose, F, Stern R.C, Matcham H. W. & Coppins B.J.  Borough of Brighton, Booth Museum of Natural History Lobaria pulmonaira is listed at

L0857 L. pulmonaria (L.) Hoffm.

On mature trees in ancient parklands; formerly locally frequent in the High Weald, now very rare. Still 41/91 at East Dean Park Wood, 1970, 1989 (on one Quercus and two Fraxinus; 51/01 Parham Park, 1988, on two Quercus; 51/53 Eridge Park, on six trees, 1968; still on one Acer and one Fraxinus, 1988. (Formerly also on the sandrocks.) [Old records (in BM) for 41/80 West Stoke; 51/22, 23 St Leonards Forest; 33 Balcombe, Ardingly Sandrocks; 53 Eridge Park and Rocks, 1842; 71 Ashes Wood; 81 Broomham, E.N. Bloomfield.]

This Atlas is now very out of date, as, in all bar one of these locations, P. lobaria has gone. However, this atlas is an extremely important evidnce of what was once in Sussex but has now gone.

Lobaria changes between 1986-1998 included atmospheric pollution, which was a major cause of decline, particularly from SO2 and acid rain. Changes in woodland management, such as heavy thinning and shorter rotation periods, also led to a decline by creating drier conditions and disrupting the continuity of old-growth forests. Habitat-related factors, such as the loss of veteran trees, and microclimatic changes were also key contributors to the population changes observed during this period Wolseley, Patricia & James, P.. (2000). Factors affecting changes in species of Lobaria in sites across Britain 1986-1998. Forest Snow and Landscape Research. 75. 319-338. 

We know see L. pulmonaria as a charaterist lichen of Atlantic woodlands (temperate rain forest) but it hard a much wider distibution, especially in Southern Oceanic Park Woodlands

Parham Park Ancient Dry Bark Communities (Lecanactidetum premneae) on Pedunculate Oak 14.09.25.

Parham Park is an SSSI and anceient deer park. Parham Park is a medieval deer park situated on Folkestone Sands at the foot of the South Downs. It has one of the richest epiphytic lichen floras in south east England. SSSI Citation

All sections of text in italics are quaotation, online sources at the end of text

Quercus robur, Pedunculate Oak

This Oak is about 10m north of the main entrace road, almost as soon as you walk through the entrance gates

Lecanographa lyncea

On dry, rough, usually well-lit bark or lignum of ancient Oak or (rarely) other species including Beech, Field Maple, Hornbeam and Turkey Oak, in ancient, usually open, parklands or pasture woodland.  A frequent component of less acidic Ancient Dry Bark Communities (Lecanactidetum premneae). 

Lecanographa lyncea grows on bark that is only rarely, if at all, wetted by stem flow and likely obtains most of its moisture from dew. The greater thermal mass of large Oaks inducing more dew deposition may be a factor in its restriction to older trees. It needs a generally humid oceanic climate, but not a very wet one where frequent stem flows extend into overhanging bark, hence encouraging bryophyte growth. It is therefore very rare or absent in temperate rainforest habitats but can be abundant in southern oceanic woods.

Sanderson (1996 & 2010) found that this lichen was completely absent from developing old growth stands that were clear felled in the early 18th century, even when the lichen was frequent in adjacent ancient old growth pasture woodland in the New Forest. It had however, recolonised pasture woodland developed over farmland abandoned after the Black Death. This suggests it typically requires over 300 years to colonise new woodlands. British Lichen Society Lecanographa lyncea

Cresponea premnea

On dry, rough, usually well-lit bark and sometimes lignum of old Oak, Holly, Yew and rarely other species including Beech, Hornbeam, Rowan and Lime; intolerant of nutrient enrichment. The dominant species of the Ancient Dry Bark Communities (Lecanactidetum premneae) on dry bark on old trees, often with Lecanographa lyncea

The Ancient Dry Bark Community (Lecanactidetum premneae) needs a generally humid oceanic climate, but not a very wet one where frequent stem flows and hence bryophyte growth extends into overhanging bark. .. . Sanderson (1996 & 2010) found that, in the New Forest, Cresponea premnea was rare in developing old growth stands that were clear felled in the early 18th century, even when the lichen was frequent in adjacent ancient old growth pasture woodland. It had however, fully recolonised pasture woodland developed over farmland abandoned after the Black Death. Cresponea premnea was a somewhat earlier colonist than Lecanographa lyncea, which was wholly absent from early 18th century stands, but still needs over over 300 years to fully colonise new woodlands. British Lichen Society Cresponea premnea