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  • Writer's pictureSim Elliott

Rock Wood SSSI, Heron's Ghyll, East Sussex: Bryophytes, Lichen, Ferns & Fungi. 13.10.23

Rock Wood is an SSSI noted for its oceanic bryophytes and it can be reached by the 29 Bus from Brighton; alight at Hendall Gate Farm stop. Regency 29 - Brighton-Tunbridge Wells and Heathfield | Brighton & Hove Buses. It is a 75 min journey from Brighton to and there is a bus every 30 minutes. Tell the driver you want to get off at that stop, as very few people get off at that stop and the drivers need quite a lot of notice.


From the bus stop, you can either walk along the path (track) that leads to Hendall Manor Fam, then take the path into Rock Wood. Alternatively you can walk up to the southern edge of Furnace Wood, where there is another footpath to Hendall Manor Farm, which runs on the south side of the Furnace Wood fence. This is the path that I took, as I wanted to look at what I initially thought was a pond in the South-East corner of Furnace Wood. However the footpath is not signed from the road, but I have included below a photo of the point on the road where the path starts. To get to the southern edge of Furnace Wood you need to walk up the A22 (going north) for about 750m, but there is no footpath, and in places no verge to walk on, so caution needs to be taken.


This the turning off the A2 to the path south of the Furnace Wood boundary fence

This is the style until the field south of Durnace Wood

Map of the Rock Wood SSSI



All sections of text in italics are quotations, sources sited.


The photographs are presented in the chronological order of my walk.


I am only an amateur naturalist; thus all identifications are provisional; if you note a mistake in identification please feel free to tell me. If you want to contact me about any aspect of this blog, email me at simeon[underscore]elliott[at]gmail[dot]com.


SSSI citation


Reasons for Notification: Rock Wood is a small ancient woodland lying on Tunbridge Wells sandstone and Wadhurst Clay. A number of different broadleaved woodland types are represented, and there has been some underplanting with conifers. A small stream and its tributary have cut through the sandstone in places creating steep sided ghylls which contain various uncommon ‘Atlantic’ bryophytes (mosses and liverworts) and ferns. The western part of the site is predominantly hornbeam Carpinus betulus coppice, with scattered oak Quercus robur standards and some coppiced hazel Corylus avellana. An ancient bank with hornbeam coppice marks the eastern edge of this type beyond which oak is the dominant tree, with holly Ilex aquifolium, and coppiced birch Betula spp and hazel. In the south-east beech Fagus sylvatica is co-dominant with oak. Ash Fraxinus excelsior is also present, while coppiced alder woodland occurs along the main stream. In the north spruce Picea sp., Douglas fir Pseudotsuga menziesii, Scots pine Pinus sylvestris have been planted underneath the mixed broadleaved canopy. Ground flora is sparse under the hornbeam coppice, beech and dense holly while under the oak and hornbeam bramble Rubus fruticosus, ground ivy Glechoma hederacea, wood-sorrel Oxalis acetosella and dog’s mercury Mercurialis perennis are found. Wild daffodil Narcissus pseudonarcissus and broad-leaved helleborine Epipactis helleborine are also recorded from Rock Wood. The ghylls feature a small waterfall which has developed where the smaller stream flows over one of several sandstone outcrops occurring throughout the wood. These ghylls have a moist, mild microclimate which is suitable for a number of ‘Atlantic’ plant species uncommon in south-east England. These include the mosses Tetraphis browniana and Diphyscium foliosum and the liverwort Marsupella emarginata. Hay- scented buckler fern Dryopteris aemula and Tunbridge filmy fern Hymenophyllum tunbrigense are also present on this site. 1003127 (naturalengland.org.uk)


South East of Furnace Wood


Furnace Wood may be a private wood but the south-east corner has open access. On the OS map there appear to be ponds in this corner; but these ponds are in fact bogs, which much sphagnum moss. Care needs to be taken as the forest floor when covered in fallen leaves looks like firm ground but part of it is bog into which you can sink up to your knees


Probably Common Smoothcap, Atrichum undulatum


Common Tamarisk-Moss, Thuidium tamariscinum


Possibly Grey Sedge, Carex divulsa


Path (not an official footpath) to the south-east corner of Furnace Wood


Probably Horn Calcareous Moss, Mnium hornum


Probably Common Feather-Moss, Kindbergia praelonga


Probably Spiky Bog-moss, Sphagnum squarrosum


Probably Fox-tail Feather-Moss, Thamnobryum alopecurum


Possibly Fringed Bogmoss, Sphagnum fimbriatum


A mossy Beech, Fagus sylvatica


Mossy silver Birch


Probably Common Feather-Moss, Kindbergia praelonga


Sphagnum bog


Possibly Mealy Forked Cladonia, Cladonia scabriuscula and Cypress-leaved Plait-Moss, Hypnum cupressiforme on log


Cypress-leaved Plait-Moss, Hypnum cupressiforme


Black Stone Flower, Parmotrema perlatum with Cypress-leaved Plait-Moss


Broad Buckler-Fern, Dryopteris dilatata


Possibly Trumpet Chanterelle, Craterellus tubaeformis with sphagnum sp. moss


Polypody fern, Polypdoum, probably Intermediate Polypody, Polypodium interjectum


Growing epiphytically on probably Goat Willow, Salix caprea


Probably Cypress-leaved Plait-Moss, Hypnum cupressiforme, with tiny grey fungus



Lichens and Mosses on rocks between Hendall Manor Farm and the entrance to Rock Wood


A beautiful rock covered in lichens and bryophytes. This rock is one of several around the base of a Hawthorne Tree in a field between Hendall Manon Farm and Rock Wood


but the crustose lichens on it (Lichen campestris, Lecidella stigmatea) I do not typically see on sandstones of the Tunbridge Wells Sand Formation (see BGS Lexicon of Named Rock Units - Result Details) in High Weald ghyll woods. It is possible that this range of crustose lichens is growing on these rocks because they have continuous sunlight. Most sandstone rocks in high weald are in woods with trees which provide a high level of shade. Alternatively these rocks are not Sandstone but imported rocks associated with landscape work carried out in the past.


The rocks


Some of the lichens and bryophytes on on this rock


Lecanora campestris


Possibly Rock Disk Lichen, Lecidella stigmatea


Common Goldspeck, Candelariella vitellina


Grey-cushioned Grimmia, Grimmia pulvinata


Rough-stalked Feather-moss, Brachythecium rutabulum


A Cladonia sp lichen


Possibly, Silvery Bryum, Bryum argenteum


Inside Rock Woods


The entrance into the woods was hidden between a Sycamore and a Chestnut - both in autumn fruit; behind these trees was a Holly in full berry


Sweet Chestnut, Castanea sativa


European Holly, Ilex aquifolium


Sycamore, Acer pseudoplatanus


On entering the wood the typically and stunning ambience of Ardingly sandstone ghyll woods was apparent - trees (oak, birch, yew, holly) growing on sandstone


And the rocks were covered in bryophytes and lichens, as is typical in high weald ghyll woods, which have maintained an oceanic microclimate similar to the former Atlantic conditions of the south east 5000 years ago.


Probably Silky Forklet-Moss, Dicranella heteromalla


Probably Horn Calcareous Moss, Mnium hornum


Forked Veilwort, Metzgeria furcata


Beech, Fagus sylvatica


English Yew, Taxus baccata


Probably Cypress-leaved Plait-Moss, Hypnum cupressiforme


This area of ground covered by dry recently-fallen leaves, surrounded by slabs of Ardingly sandstone, turned out to be a bog, into which I sunk up to me knees.


Toothed Plagiothecium Moss, Plagiothecium denticulatum


Possibly Clustered Feather-Moss, Rhynchostegium confertum


Oak Pin fungi, Cudoniella acicularis


Beefsteak Polypore, Fistulina hepatica


Broad Buckler-Fern, Dryopteris dilatata


Probably Honeycomb Coral Slime Mold, Ceratiomyxa fruticulosa


Male Fern, Dryopteris filix-mas


Possibly Snakewort, Conocephalum salebrosum


The ghyll (Hero's Ghyll) rises from a spring in Ashdown Forest and is a tributary of the River Ouse


A Bonnet, Mycena sp., growing on a fallen leaf


The forest floor covered in Broad Buckler, Male and Scaly Male ferns


A Feather Moss sp., Order Hypnales


Common Pocket-Moss, Fissidens taxifolius


A dry tributary stream to the main ghyll


Probably Elegant Silk-Moss, Pseudotaxiphyllum elegans


Probably, Elegant Silk-Moss, Pseudotaxiphyllum elegans


Possibly Ring Pellia, Pellia neesiana


Black Spleenwort, Asplenium adiantum-nigrum


Mossy outcrop


Probably White Earwort, Diplophyllum albicans


Possibly Lesser Pocket-Moss, Fissidens bryoides


Artist's Bracket, Ganoderma applanatum



Probably Fluffy Dust Lichen, Lepraria finkii. Lepraria lichen are common on sandstone outcrops, and sometimes grow over mosses


Common Earthball, Scleroderma citrinum


Fairy Inkcap, Coprinellus disseminatus


Honeycomb weathering on the sandstone


Honeycomb weathering produces extensive networks of small cavities that form on rock surfaces. These patterns initially develop as many shallow depressions, but continued development produces deep chambers that are separated by thin septa of unweathered rock (Figure H9). Individual cavities are typically several centimeters in width and depth, the shape often being controlled by bedding planes, foliation, or other structural features of the rock in which they occur. In many localities the holes occur in association with a hardened surface layer formed when dissolution of ferruginous minerals has been followed by precipitation of ferric hydroxides near the outcrop surface. The thickness of this hardened layer may range from a few millimeters to several centimeters. Honeycomb Weathering | SpringerLink


Pincushion Moss, Leucobryum glaucum


Scaly Male Fern, ComplexDryopteris affinis




Probably Bifid Crestwort, Lophocolea bidentata


Male Fern, Dryopteris filix-mas



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