Two special finds: Dumortier's Liverwort & Epiphytic Polypody Ferns at Fairlight Glen. 14.10.23
I visited Fairlight Glen on 14.10.23 to enjoy its amazing bryophytes and ferns; I was hoping to find Dumortier's Liverwort Dumortiera hirsuta, as I knew it was there and had looked for it on three former occasions but not found it. Finding it finally and a Polypody Fern Polypodium sp. growing abundant on the branches of a Sessile Oak, Quercus petraea, was a real pleasure.
I reached Fairlight Glen by train and bus, for details of public transport see: Fairlight Glen; from the Dripping Well to the Beach. Ferns, Bryophytes and Lichen. 19.06.23
All sections of text in italics are quotations, sources sited.
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The Dripping Well and its Dumortier's Liverwort
Dumontier's Liverwort is famously known (amongst bryologists) to be at Fairlight Glen; and its presence there has been publicised in the press:
Hastings Country Park is the best site in the UK for the rare plant Dumortier’s Liverwort.
That’s according to a survey on behalf of Natural England that says the plant, known in Latin as, Dumortiera hirsuta, is thriving because of improved management of Fairlight Place Farm at Hastings Country Park.
The first record of D.hirsuta in Hastings is from 1883, where it was often reported as plentiful. The present survey recorded a similarly large population along 425m of the main stream and the lowest 15m of the main side tributary, concentrated at the top of the valley around Dripping Well.
Colin Fitzgerald, lead councillor for parks and open spaces said: “Following serious slurry pollution to the Site of Special Scientific Interest (SSSI) at Fairlight Glen in 2000, HBC brought the tenanted farm back into public management.
“We changed it from an intensive dairy operation to a low-intensity mixed farming regime focused on biodiversity enhancement. The pollution from the cattle slurry nearly wiped out the plant, but we stopped the pollution and reversed the decline in this rare and important species.
“It is fantastic to see our conservation efforts paying off with rare plants thriving in the glens.’
The plant is thriving with half of all England’s Dumortier’s Liverwort now found in Hastings Country Park Nature Reserve. Half the nation’s Dumortier’s Liverwort is right here in Hastings – Hastings In Focus February 14, 2020
I have looked at the bryophytes at the amazing Dripping Well, a small waterfall in the ghyll which runs from a spring to the sea at Fairlight Beech, which has created a steep-sided ravine, on various occasions and not seen Dumontier's Liverwort; but I realised they are hiding in plain sight: they were there in front of my eyes if I had looked at the right place.
The wall of bryophytes (mostly liverworts) on the face of the Dripping Well
Some of the liverworts form stalactite-like structures.
And ... ta-dah ... Dumortier's Liverwort, towards the top of the mat of liverworts.
A conspicuous thallose liverwort that often forms mats. D. hirsuta is somewhat aromatic, with broad, flat, semi-translucent, dichotomously branching thalli up to 2 cm wide. The thallus is dull and dark green, sometimes yellow-green. It lacks air pores (except sometimes a few indistinct pores near the tip) and has no network of lines on its upper surface. The thallus margins and undersides bear scattered, stiff bristles. The male receptacles are bristly and borne on a very short stalk. Female plants have long-stalked, bristly receptacles borne at the thallus tip; each receptacle is flat-topped with 6 to 12 short, spreading lobes.
D. hirsuta is unique in its combination of having bristles, no air pores or network of lines on its thalli, and stalked receptacles, and is therefore unlikely to be confused with other Marchantiales species growing in damp shady habitats, such as Conocephalum conicum and C. salebrosum (p. 255), Lunularia cruciata (p. 252) and Marchantia polymorpha (p. 258), all of which have conspicuous air pores on the upper surface.
This is a rare, oceanic liverwort growing in shady, humid places by streams and waterfalls, usually on rocks or earthy banks that are often or always moist or wet, under boulders or in caves and shady recesses. Dumortiera-hirsuta.pdf (britishbryologicalsociety.org.uk)
Distribution map from Atlas-of-British-and-Irish-Bryophytes-V1-87.pdf (britishbryologicalsociety.org.uk)
A couple of other beautiful bryophytes from the dripping well.
The liverwort: Endive Pellia, Pellia endiviifolia, showing its beautiful autumn/winter growth form; In autumn and early winter they develop numerous, narrow (to about 6 mm wide) branches at the tips (see right photograph) which are sometimes so abundant that they obscure the broader thalli on which they have developed. Pellia-endiviifolia.pdf (britishbryologicalsociety.org.uk)
The moss Shining Hooker, Hookeria lucens
The shoots of H. lucens are 2–6 cm long, pale or bright green, and are rather 2-dimensional, although the flattening is not as extreme as in genera such as Fissidens or Schistostega. The most striking character of the leaves is the enormous, more or less hexagonal cells which are visible to the naked eye and extend to the margins (there is no border of narrow cells). The leaves are about 5 mm long, 3 mm wide, rounded at the tip and have no nerve. The dark brown capsules are quite common, about 2 mm long, borne on a seta about 2 cm tall, and carried horizontally or sloping slightly downwards.
The Sessile Oak and its Polypody Ferns
On this Sessile Oak, Quercus petraea, half way down Fairlight Glen, close to where the north-south path above the beach intersects with the east-west path, there were lots of epiphytic Polypody ferns Polypodium sp. prob. P. interjectum. Polypodium growing epiphytically on trees is rare in Sussex. I have only seen it before in Furnace Wood near Herons Ghyll and at Fore Wood near Crowhurst, but not on Sessile Oak. I have seen lots of Polypodium fern on Sessile Oak in temperate rain forests in Snowdonia and North West Scotland ; see Coed Felenrhyd and Llennyrch, Maentwrog, Wales. Wild flowers, ferns, bryophytes & lichens. 15.08.23 and Scotland 6: Glen Nant. NNR; temperate rain forest. 13.05.23
Put more simply: temperate rainforests are very damp woodlands – so damp that plants grow on other plants. These plants are known as ‘epiphytes’. If you want to recognise temperate rainforest in Britain, the key indicator is an abundance of mosses, lichens and polypody ferns festooning the branches and trunks of trees. What is a temperate rainforest? – Lost Rainforests of Britain
Rainforests in the UK are part of the Coastal Temperate Rainforest biome and can be found in pockets on our Atlantic coasts. They occur where there is a wet and humid climate, clean air, and coastal and/or upland ancient woodland. It does not matter how often I visit them, it always takes my breath away that we have rainforests right here on our magnificent Isles. These drippy, green woodlands are mystical, magical places where moss, ferns and lichens ramble over crags, boulders and cover entire trees and river gorges.
Dorset is too far east for a rainforest, yet our woodlands still harbour the evergreen flat fronds of the little polypody ferns that cling to the crevices of moss-covered branches. Ferns are ancient plants that first appeared about 400 million years ago. Rather than flowers with seeds, they reproduce by spores carried by the wind and can survive for decades in the soil. Meditations in nature: Ferns of the rainforest | The New Blackmore Vale Magazine | In Print & Online