Sunday 19th February 2017 – Sand Point and Middle Hope, Weston-super- Mare

Sand Point is a narrow isthmus of carboniferous limestone reaching eastward in to the sea north of the coastal resort of Weston-super-Mare. It is one of two such peninsulas which frame WSM, the other being Brean Down to the south of the town. Both sites have high bryological interest but being very exposed, they are usually quite windy, causing many bryophytes to desiccate quickly. Fortunately for this field meeting, conditions were relatively good, with light winds and the ground still moist underfoot following recent rainfall.

Sand Point (including Swallow Cliff) has been surveyed intermittently in the past and most recently in 2012. Our group went out armed with an inventory of moss and liverwort species previously seen, but didn’t really expect to add much to it.

Members of the group getting down to business with the tiny acrocarps on Sand Point. Sharon Pilikington

Members of the group getting down to business with the tiny acrocarps on Sand Point. Sharon Pilikington

Certain iconic and very rare species known from Sand Point include Cheilothela chloropus (the oddly-named Rabbit-moss) which has been known in some quantity there for many years and Weissia levieri, which is also known from Brean Down. Many other interesting species had been noted in the past, so we duly set off to try to track as many down as possible.

After dodging the inevitable dog mess on the path up on to the top of the down, we came quickly upon an area where a heavily trampled wide turf path followed the ridge. Low limestone outcrops punctuated the ground in and around the path and here we fell to the ground to find our first patches of C. chloropus. Although the BBS Field Guide boldly states that this is an ‘easy plant to recognise’, when it is growing as scattered stems among lookalikes such as Pseudocrossidium hornschuchianum, Trichostomum crispulum and Didymodon fallax it can be a tricky species to identify. So we spent much time at this particular spot. Had we known then that there is a much larger sub-population a little further along the ridge we may not have lingered so long, but as we also spotted Bryum kunzei, Scleropodium touretii, Scorpiurium circinatum and Bryoerythrophyllum ferruginascens in the same place it didn’t matter. B. ferruginascens was found new to Somerset by Des Callaghan when he surveyed Brean Down in 2012, although he did not report it from Sand Point. Since then this characteristically upland moss has been found to be widespread on in the Mendip Hills and is now known from 30 different 1km squares in N. Somerset V.-c. 6.

Rabbit Moss Cheilothela chloropus on Sand Point. Sharon Pilkington

Rabbit Moss Cheilothela chloropus on Sand Point. Sharon Pilkington

In south-facing limestone grassland a little further on, we found the prickly-looking stems of Rhynchostegium megapolitanum, a coastal species that resembles a Brachythecium more than a Rhynchostegium. Close examination of the leaves revealed its characteristic twisted leaf tips. Nearby, a rather flat, dark hoary patch on a nearby rock proved to be Grimmia dissimulata, a slightly anonymous-looking species that can sometimes turn up on mortar in old churchyards.

Previous bryological attention appears to have – not surprisingly – focussed on the south-facing parched CG1 grassland where most of Sand Point’s specialities occur. However, where the point drops to the sea on the north side, there are a number of large limestone outcrops and small cliffs with a very different kind of climate. With this in mind, we clambered down to look at some of these and were immediately rewarded with some splendid-looking black patches of the uncommon liverwort Marchesinia mackaii. Other species flourishing on the northern side included Lejeunea lamacerina, which is scarce in N. Somerset and hadn’t been noted from Sand Point before, and common species such as Anomodon viticulosus, Porella platyphylla and Ctenidium molluscum. Frullania tamarisci was found in the turf nearby and a relatively large population of the thalloid liverwort Riccardia chamedryfolia was seen on damp eroded ground of a shaded path at the foot of the slope.

Towards the eastern end of Sand Point there is rocky, summer-parched limestone grassland with a strong population of the rare umbellifer Trinia glauca (Honewort). This is where W. levieri has been reported in the past and it took us very little searching to find some. It is one of only a few Weissia species with immersed capsules and differs from the commoner W. longifolia in having dehiscent lids. At least one other species of Weissia with an elongate seta was also present in the same area (possibly W. perssonii?) but frustratingly the capsules were not quite mature enough to allow us to identify the species.

Weissia levieri on Sand Point. Sharon Pilikington

Weissia levieri on Sand Point. Sharon Pilikington

This part of Sand Point site also proved good for a number of other small mosses, including Microbryum starckeanum, M. rectum and Fissidens incurvus. Where the cliff fell down to the sea, Tortella flavovirens with its characteristic yellow-green colour was quite plentiful and a few people with sharp eyes found the young capsules of Bryum torquescens nearby. This relatively rare species is closely related to the very common B. capillare and care must be taken in separating them. The best way is to search plants with young capsules for the male antheridia which if present confirm B. torquescens, as B. capillare is dioicous and so does not have male and female reproductive structures on the same plant. In addition, B. torquescens usually grows directly on soil and when dry its leaves do not corkscrew around each other like B. capillare.

Not surprisingly, epiphytes are not common on such an exposed site although back at the car park some of us did find a relatively sheltered tree hosting lots of Orthotrichum tenellum and other common species.

Sharon Pilkington

Posted in Past.

Leave a Reply

Your email address will not be published. Required fields are marked *