Spicey Gill, Ilkley Moor

Wednesday 7th June 2023

Leader: Laurie Wildwood

Number of attendees: 13

What better way to spend a warm, sunny evening than a gentle saunter on Ilkley Moor? Laurie took us on a circular walk in the Spicey Gill area of the moor which included visiting an abandoned quarry and an interesting moorland flush. Moorland habitat can be rather species-poor for higher plants, but as today’s focus was bryophytes (mosses and liverworts), there was no shortage of plants to admire.

Before I highlight some of the bryophytes we saw, I’ll mention some of the higher plants we encountered along the way. A few metres from Keighley road was the garden escape Prickly Heath (Gaultheria mucronata) which was a good size and looking well established. The tips of the leaves have a short point (called a mucro) which was clearly visible. In the damp ground of a moorland flush it was good to see Round-leaved Sundew (Drosera rotundifolia), Marsh Willowherb (Epilobium palustre), Bog Stitchwort (Stellaria alsine) and Lesser Spearwort (Ranunculus flammula).

Nearby was Lemon-scented Fern (Oreopteris limbosperma). The spores had not yet developed but we examined the underside of the frond to see the small orange glands dots which are responsible for the lemon scent of crushed leaves.

On the moorland and heathland, there were the usual suspects of acid-loving plants, but the Sheep's Sorrel (Rumex acetosella) was looking good, flowering on mass in areas of shallower soil where bracken hadn’t taken hold. Laurie also pointed out Spreading Meadow-grass (Poa humilis) growing at the edge of the path, a species that is generally under-recorded.

Many of the attendees had no or little knowledge of how to identify even common bryophytes so we were grateful to Laurie for pointing out some of the species and giving us tips on identification. The first moss Laurie showed us was Dotted Thyme-moss (Rhizomnium punctatum), which he found by a bridge on Keighley Road. This has relatively large, egg-shaped leaves, 5-6mm long. Up on the moorland was Fountain Apple-moss (Philonotis fontana), the upright, apple-green shoots standing out from the surrounding vegetation. Near by, Bog Bead-moss (Aulacomnium palustre) was distinctive in having pale yellow-green leaves which contrasted with the orange-brown rhizoids (root-like structures) which covered the stem.

In an area of boggy ground, we looked at 4 different species of Sphagnum. Laurie demonstrated how Fringed Bog-moss (Sphagnum fimbriatum) got its name: if you pull off the top-heavy head (capitulum) of the shoot and examine the top of the stem, you’ll see a ragged or ‘fringed’ edge (as indicated by the arrow on the below photograph). This is formed by the fringed upper margin of the stem leaves which form a ruff around the stem. This species has a conspicuous terminal bud on the capitulum (Laurie called this a ‘nose-cone’), which sticks up higher than the rest of the shoot.

Another distinctive looking Sphagnum was Cow-horn Bog-moss (Sphagnum denticulatum), where the outer capitulum branches look like curved, pointed cow-horns. Spraying the shoots of Red-stemmed Feather-moss (Pleurozium schreberi) with water from a spray bottle, Laurie showed us how the shoots turn a more vivid red when wet. On a boulder in the stream was the liverwort Water Earwort (Scapania undulata), which has rounded leaf lobes, appressed to each other, with the shoot tips looking to me like soup ladles. Another distictive looking liverwort was Atlantic Pawwort (Barbilophozia atlantica), a species of upland Britain which has 3-lobed leaves.

Back at the cars we thanked Laurie for leading us on such an enjoyable walk and enlightening us on the world of bryophytes. Even if identifying bryophytes to species level seems too daunting, it’s well worth getting out your hand lens to appreciate the diversity and beauty of these tiny plants.

In this account, I’ve included the common names of bryophytes (as given in Mosses and Liverworts of Britain and Ireland - a field guide by the British Bryological Society, 2010) but most of the common names of bryophyes are relatively newly devised and species are more usually referred to by their scientifc name. I took the bryophyte photographs using a microscope from samples taken on the day but these features were clearly visible using a hand lens in the field.

Text and photographs by Susan