I am not going to reveal where we found these species as the lichen Tree Lungwort, Lobaria pulmonaria, and Tunbridge Filmy-fern, Hymenophyllum tunbrigense, are very rare species in Sussex. All of these species were found in area of High Weald Ghyll Woodland, except the waxcaps which were seen on grassland adjacent to the woodland. Tree Lungwort and Tunbridge Filmy-fern are more common in Atlantic Woodlands, and are characteristic of temperate rain forest. I went on this nature outing with a friend and expert naturalist who knew where these species were in Sussex. I have seen Tree Lungwort in the temperate rainforest of north-west Scotland, in Bute and Argle (Glen Nant, Glasdrum and Dunollie Wood) but never before in Sussex. I have seen Tunbridge Filmy-fern in Coed Felenrhyd & Llennyrch and in one other place in Sussex. Tunbridge Filmy-fern is known in a few places in Sussex, as far as I know Tree Lungwort is only known in one place in Sussex.
We also saw Lemon-scented Fern Oreopteris limbosperma, and possibly Tattered Jellyskin Lichen, which were also new sightings for me.
The ancient Ash, Fraxinus excelsior, on which the Tree Lungwort was located. One of our most beloved trees. Ash is one of the most common trees in the UK, but as ash dieback sweeps through, is it set to be erased from our countryside? Ash (Fraxinus excelsior) - British Trees - Woodland Trust
Tree Lungwort, Lobaria pulmonaria
Habitats
Occurs on broad-leaved trees, low scrub, heather and mossy rocks, rarely on old walls in the west and on conifers in western Scotland. Away from western Scotland it is a good indicator of ancient woodland, and in lowland areas of southern England is found in former medieval parklands and old forests such as the New Forest. Lobaria pulmonaria is the most typical and constant memebr of the foliose Lobarion communities, with species of Lobaria, Sticta, Nephroma, Degelia, Pannaria, Parmeliella, and the crustose "old forest" species that grow on bryophytes such as Homalothecium sericeum and Isothecium myosuroides.
Threats & Status Native. Locally abundant but rare and decreasing in parts of the south and east and now extinct from former sites in the midlands, East Anglia, and east of Hereford and Gloucester. It is very sensitive to changing habitat structure and woodland management, also to atmospheric pollution, especially SO2 and acid rain. Lobaria pulmonaria | The British Lichen Society
Distribution map from Lobaria pulmonaria | The British Lichen Society
Possibly Scytinium lichenoidesi,
Distribution map from Scytinium lichenoides | The British Lichen Society
Peltgera praetextata, Scaly Dog Pelt Lichen
Lemon Centred Fern, Oreopteris limbosperma
Distribution map from Oreopteris limbosperma (All.) Holub in BSBI Online Plant Atlas 2020
Trend in abundance: significantly declining abundance
The distribution of this species in the uplands, where it can be locally abundant, is stable. Many of the losses in the lowlands occurred before 1930, caused especially by the destruction of heathland. This decline continues and remaining populations in south-eastern England are small and vulnerable. The factors responsible for losses are varied, but include changes to woodland management, drainage and eutrophication.
