Glenariff Glen

Also within

Antrim County Antrim Coast and Glens Scenic Area

Habitats

Fast flowing river and stream, Hedgerow scrub

Geology & landscape

Geological Feature: Fissure, Gorge / Ravine · Geological Period: Paleogene · Rock Type: Basalt

Landscape processes: Fluvial, Volcanic / Igneous

Description

Glenariff Glen Bryophyte assemblage, Higher plant assemblage The area is of special scientific interest for its rich assemblage of rare species, with both higher plants and bryophytes mosses and liverworts well represented. Glenariff Glen is situated approximately 5 km south-west of Waterfoot, in the largest of the Antrim Glens. The area is underlain by Palaeogene age rocks, dominated by the Lower Basalt Formation. Almost exclusively comprising basalt, these rocks formed as lava flows associated with fissure type eruptions. The soils at Glenariff Glen have developed from the basalt parent rock. Typically they have poor drainage characteristics and are known as surface water and groundwater gleys. Glenariff Glen forms a steep-sided valley around the Glenariff River which includes several small waterfalls, in addition to Ess-na-Larach, the main waterfall. The deep glen, shaded by surrounding woodland provides a cool, humid environment. In some places, the valley sides are so steep that there is little or no soil present. The rock faces are often dripping in water from flushes at the top of the ravine, providing an ideal habitat for mosses and liverworts, which often form a luxuriant carpet on the walls of the glen. The extensive spray-zone around Ess-na-Larach waterfall has one of the best-developed communities of bryophytes associated with humid ravine habitats in north-eastern Ireland. Two rare bryophytes are found on the steep basalt rocks around the waterfall, including ragged notchwort Leiocolea heterocolpos, which is listed as Critically Endangered in the Irish Bryophyte Red Data Book in preparation. It was first recorded in Ireland in 1969 at Glenariff Glen and the site remains the only known location for this species in Ireland. The other rare species is rigid apple moss Philonotis rigida, which is listed as Vulnerable in the Irish Bryophyte Red Data Book in preparation. Glenariff Glen hosts the only known extant population of this species in Northern Ireland, with only one other historical record in County Fermanagh in 1961, which has not been relocated. Other bryophytes found on the site include the mosses hart's tongue thyme moss Plagiomnium undulatum, fox tail feather moss Thamnobryum alopecurum, purple stalked pocket moss Fissidens osmundoides, comb moss Ctenidium molluscum and dotted thyme moss Rhizomnium punctatum and the liverworts great scented liverwort Conocephalum conicum, Hutchins' hollywort Jubula hutchinsiae and lesser rough earwort Scapania aequiloba. The glen is densely wooded, with both semi-natural woodland and planted woodland, the latter consisting of beech Fagus sylvatica and conifers. Semi-natural woodland occurs in places along the river and consists of a canopy dominated by ash Fraxinus excelsior, goat willow Salix caprea and hazel Corylus avellana. Close to the river, there are occasional wych elm trees Ulmus glabra and non-native sycamore Acer pseudoplatanus. Holly Ilex aquifolium and rowan Sorbus aucuparia occur in the shrub layer. The woodland ground flora is often dominated by stands of ramsons Allium ursinum, bluebell Hyacinthoides non-scripta, wood sorrel Oxalis acetosella, wood anemone Anemone nemorosa and lesser celandine Ranunculus ficaria, with opposite-leaved golden-saxifrage Chrysosplenium oppositifolium often abundant in wetter areas. Common associates include common dog violet Viola riviniana, wild strawberry Fragaria vesca, herb Robert Geranium robertianum, honeysuckle Lonicera periclymenum, lords and ladies Arum maculatum, primrose Primula vulgaris, woodruff Galium odoratum, wood sedge Carex sylvatica, bugle Ajuga reptans, hedge woundwort Stachys sylvatica, germander speedwell Veronica chamaedrys, devils-bit scabious Succisa pratensis, sanicle Sanicula europaea, barren strawberry Potentilla sterilis and wood avens Geum urbanum. Ivy Hedera helix occurs in the ground flora in places. Rocky ledges often support grasses such as wood melick Melica uniflora and wood fescue Festuca altissima, as well as ferns such as maidenhair spleenwort Asplenium trichomanes and hart's-tongue Phyllitis scolopendrium. Rare and scarce plants include common wintergreen Pyrola minor and intermediate wintergreen Pyrola media, with beech fern Phegopteris connectilis on rock ledges and steep rock faces. The site also supports a range of invertebrates, including a number of rare Molluscs which are listed in the Irish Red List for Non-marine Molluscs. Of particular note is the plaited snail Spermodea lamellata, which is found in deep stable leaf litter and is listed as Endangered in the Irish Red List, having declined dramatically in the last 3.0 years in Ireland. Other species present which are listed as Vulnerable in the Irish Red List include the brown snail Zenobiella subrufescens, which is an old woodland relict species and the point snail Acicicula fusca, which is almost endemic to Britain and Ireland, with only small populations in France, Belgium and Germany. Glenariff Glen provides an important habitat for plants and animals, including birds, mammals and invertebrates. It is hoped that continued sensitive management of the area will ensure that the rich assemblage of species is maintained. https://www.daera-ni.gov.uk/publications/glenariff-glen-assi

Species mentioned

Show the 45 species mentioned in the description, with red-list status ▾

Insects to look out for

These moths, butterflies and beetles are known to feed on plants recorded at this site, and carry a notable UK conservation status — but a host-plant being present doesn't mean the insect has actually been recorded here. Treat this as "worth watching for," not a confirmed sighting.

Species	Status	Via host-plant
High brown fritillary Fabriciana adippe	Critically Endangered	Viola riviniana
Pearl-bordered fritillary Boloria euphrosyne	Endangered	Viola riviniana
The lappet Gastropacha quercifolia	Endangered	Salix spp.
Duke of Burgundy Hamearis lucina	Endangered	Primula vulgaris
Heath fritillary Melitaea athalia	Endangered	Veronica chamaedrys
Scarce vapourer Orgyia recens	Endangered	Corylus avellana, Fagus sylvatica, Salix spp., Ulmus spp.
White-letter hairstreak Satyrium w-album	Endangered	Ulmus glabra, Ulmus spp.
Mouse moth Amphipyra tragopoginis	Vulnerable	Fragaria spp., Salix caprea
The sprawler Asteroscopus sphinx	Vulnerable	Corylus avellana, Fagus sylvatica, Fraxinus excelsior, Salix spp., Ulmus spp.
Broom moth Ceramica pisi	Vulnerable	Ulmus spp.
Scarce chocolate-tip Clostera anachoreta	Vulnerable	Salix spp.
Mottled umber Erannis defoliaria	Vulnerable	Acer pseudoplatanus, Corylus avellana, Fagus sylvatica, Lonicera periclymenum, Salix spp., Sorbus aucuparia, Ulmus spp.
Marsh fritillary Euphydryas aurinia	Vulnerable	Lonicera periclymenum, Succisa pratensis
Satyr pug Eupithecia satyrata	Vulnerable	Galium spp., Salix spp.
Bedstraw hawk-moth Hyles gallii	Vulnerable	Galium spp.
White admiral Limenitis camilla	Vulnerable	Lonicera periclymenum
The lackey Malacosoma neustria	Vulnerable	Corylus avellana, Salix spp., Ulmus spp.
Pale brindled Phigalia pilosaria	Vulnerable	Corylus avellana, Fraxinus excelsior, Salix caprea, Ulmus glabra
Grizzled skipper Pyrgus malvae	Vulnerable	Fragaria vesca, Geum urbanum, Potentilla sterilis
Pale eggar Trichiura crataegi	Vulnerable	Corylus avellana, Salix spp.
Flounced chestnut Agrochola helvola	Near Threatened	Salix spp., Ulmus spp.
Beaded chestnut Agrochola lychnidis	Near Threatened	Salix spp.
Grey chi Antitype chi	Near Threatened	Salix caprea
Purple emperor Apatura iris	Near Threatened	Salix caprea
Garden tiger Arctia caja	Near Threatened	Sorbus aucuparia
Small pearl-bordered Boloria selene	Near Threatened	Viola riviniana
Minor shoulder-knot Brachylomia viminalis	Near Threatened	Salix caprea
Dusky-lemon sallow Cirrhia gilvago	Near Threatened	Ulmus glabra
The sallow Cirrhia icteritia	Near Threatened	Salix spp., Ulmus glabra
Small heath Coenonympha pamphilus	Near Threatened	Festuca spp.
Dingy mocha Cyclophora pendularia	Near Threatened	Salix caprea
Large thorn Ennomos autumnaria	Near Threatened	Acer pseudoplatanus, Corylus avellana, Salix spp., Ulmus spp.
September thorn Ennomos erosaria	Near Threatened	Fagus sylvatica
Dusky thorn Ennomos fuscantaria	Near Threatened	Fraxinus excelsior
Autumnal rustic Eugnorisma glareosa	Near Threatened	Galium spp., Hyacinthoides non-scripta
Grey pug Eupithecia subfuscata	Near Threatened	Salix spp.
Double dart Graphiphora augur	Near Threatened	Salix spp., Ulmus spp.
Dark-barred twin-spot carpet Xanthorhoe ferrugata	Near Threatened	Galium spp.

Host-plant data: Cook et al. (2025), Traits data for the butterflies and macro-moths of Great Britain and Ireland, 2024, UK Centre for Ecology & Hydrology / Butterfly Conservation; and Padovani et al. (2020), Database of Insects and their Food Plants (DBIF), UK Centre for Ecology & Hydrology (both Open Government Licence). Contains data supplied by UK Centre for Ecology & Hydrology.

Plant communities