Great bryophytes at Great Tew

Despite Storm Ciara pummelling parts of Britain, no less than five bryologists turned out for our trip to part of the Great Tew estate (the valley at the bottom of SP3730). In the event, despite getting rather wet, the valley sheltered us from the worst of the wind, and the only slightly hairy moment was the explosive crack of a branch coming down further along the valley.

Although bryologists have visited the Great Tew area previously (e.g. Eustace Jones recorded Grimmia orbicularis on the estate, and mentions a record of Orthotrichum tenellum in a "wet wood in valley north of Great Tew"  in his 1953 paper on the mosses of Berkshire and Oxfordshire), very few localised records actually exist in the database of the British Bryological Society (older records tend only to have been entered as hectad summaries). This, then, was a great chance to explore a private woodland (we had permission!) and make some localised records for an area that is not well-represented in records databases.

After picking up various common pleurocarps after dropping into the valley, we also found Isothecium alopecurum on the roots of ash and fertile Cirriphyllum crassinervium nearby on soil. Soon after we found one of the things that we had been hoping for, a tufa-forming stream emerging out of the valley-side, as is often found in cuttings and valleys on the Oolite in the north of Oxfordshire. This particular one was not particularly blessed with bryological interest, although a large stand of Palustriella commutata featured in the centre of the stream, accompanied by Cratoneuron filicinum and Pellia endiviifolia.

Palustriella commutata clump in tufaceous spring

Soon after, an uncommon sight in Oxfordshire was seen, that of Plagiomnium undulatum fruiting. Jones (1953) listed this species as "sterile" in Oxon., and still considered the fact of its fruiting "rare or very rare" after forty more years bryologising in the county (Jones, 1991).

Plagiomnium undulatum in fruit at Great Tew.

By this point of the day we were rather sodden, and thoughts were turning towards home. Perhaps the nicest thing of the afternoon was a good population of the liverwort Plagiochila asplenioides growing along a track through the wood further up the valley side. Whilst this livewort is fairly frequent in ancient woods on heavy basic soils, it is not common in Oxfordshire overall, and is always nice to see.

Plagiochila asplenioides at Great Tew.

And finally, a nice photo of the epiphytic liverwort Metzgeria violacea that seemed extremely happy in the humid environment of this hidden valley.

Metzgeria violacea

Oh, and for the non-bryologists, we also saw Dryopteris dilata growing epiphytically in the crown of a fallen oak, which is not a habitat most Floras list!

Dryopteris dilata growing as an epiphyte on oak (foreground; background fern is Polypodium interjectum)

The full list of bryophytes seen in the valley at Great Tew is given below:

Amblystegium serpens var. serpens	Hypnum cupressiforme var. resupinatum	Zygodon conoideus var. conoideus
Brachythecium rivulare	Isothecium alopecuroides	Conocephalum conicum s.str.
Brachythecium rutabulum	Isothecium myosuroides	Frullania dilatata
Bryum capillare	Kindbergia praelonga	Lophocolea bidentata
Calliergonella cuspidata	Orthotrichum affine	Metzgeria consanguinea
Cirriphyllum crassinervium	Oxyrrhynchium hians	Metzgeria furcata
Cratoneuron filicinum	Oxyrrhynchium schleicheri	Metzgeria violacea
Cryphaea heteromalla	Palustriella commutata s.str.	Pellia endiviifolia
Didymodon sinuosus	Plagiomnium undulatum	Radula complanata
Fissidens gracilifolius	Plagiothecium nemorale	Atrichum undulatum
Fissidens incurvus	Rhynchostegium confertum	Cirriphyllum piliferum
Fissidens taxifolius var. taxifolius	Syntrichia virescens	Didymodon insulanus
Homalothecium sericeum	Thamnobryum alopecurum	Leskea polycarpa
Hygrohypnum luridum	Thuidium tamariscinum	Orthotrichum pulchellum
Hypnum cupressiforme var. cupressiforme	Ulota phyllantha	Orthotrichum stramineum
		Plagiochila asplenioides

Bryophytes of Dorchester (Oxfordshire)

Three bryologists met at Dorchester Abbey (SU5794) on a grey, drizzling morning for the fifth excursion of the season. The Abbey graveyard and buildings proved to have a lot to offer, with a grand total of 41 species, pipping our previous season's best churchyard at Bletchingdon (36 species). Probably the top find was Gyroweisia tenuis on the east facing walls of the Abbey. Gyroweisia can be easily confused with other species, particularly Leptobarbula berica, and the Sussex Bryological Group have an excellent blog on this topic.

Gyroweisia tenuis habitat (with Porella platyphylla in foreground)

The other nice find in the churchyard was Syntrichia papillosa. This is a species that appears to be spreading in lowland Britain, possibly helped by eutrophication of a range of substrates from various sources of nitrogen (e.g. NOx from car exhausts). On the other hand, it may be that the species is just recovering from losses during an earlier period of substrate acidification from SO2 pollution (and the loss of hedgerow elms). For example, Eustace Jones notes that Herbert Napier (recording in Oxon. 1909-1914) reported it as "not uncommon" and suggested that the species had increased since the time of Boswell (recording in Oxon. 1858-1897). Jones himself reported S. papillosa as "certainly rare" (this would have applied to the 1935-1953 period) and describes the species as typically only found in single locations within sites (and gives hedgerow trees, "usually elm", as the habitat). Perhaps at this point the species was still widespread but locally rare, meaning that it was often overlooked during surveys. Certainly it appears to have subsequently declined, as it was only recorded twice in Oxon. in the period 1953-1991 (Jones, 1991).

At Dorchester we found nice stands of the plant on a tombstone, but also on the slats of a park bench, suggesting a novel mode of gemmae movement! See the two pictures of the photogenic S. papillosa below:


The full list from Dorchester Abbey appears below:

Amblystegium serpens	Grimmia pulvinata	Rhynchostegium confertum
Barbula convoluta var. convoluta	Gyroweisia tenuis	Rhynchostegium murale
Barbula unguiculata	Homalothecium sericeum	Rhytidiadelphus squarrosus
Brachythecium rutabulum	Hypnum cupressiforme	Schistidium crassipilum
Bryum argenteum	Hypnum cupressiforme var. lacunosum	Syntrichia latifolia
Bryum capillare	Kindbergia praelonga	Syntrichia montana
Bryum rubens	Orthotrichum anomalum	Syntrichia papillosa
Calliergonella cuspidata	Orthotrichum cupulatum	Zygodon viridissimus var. viridissimus
Didymodon fallax	Orthotrichum diaphanum	Lophocolea bidentata
Didymodon insulanus	Oxyrrhynchium hians	Lunularia cruciata
Didymodon luridus	Phascum cuspidatum	Porella platyphylla
Didymodon nicholsonii	Plagiomnium rostratum
Didymodon sinuosus	Pseudocrossidium hornschuchianum
Didymodon vinealis	Pseudoscleropodium purum
Fissidens taxifolius var. taxifolius	Rhynchostegiella tenella

After lunch we walked a circuit through the Dyke Hills (SU5793) west of Dorchester, and then followed the Thames anti-clockwise back to the town.

The (flooded) Dyke Hills in winter.

The Dyke Hills are an Iron Age earthwork, and covered in a slightly improved form of calcareous grassland, the hills themselves presumably being formed from river gravels excavated locally. The bryophyte flora reflects this. After some time searching, we came up with the following, fairly meagre, list:

Weissia species	Homalothecium lutescens
Barbula unguiculata	Oxyrrhynchium hians
Brachythecium rutabulum	Phascum cuspidatum
Bryum rubens	Plagiomnium affine
Fissidens dubius	Pseudoscleropodium purum

The riverside circuit turned up several expected riverside bryophytes, including Syntrichia latifolia, Cinclidotus fontinaloides, and Dialytrichia mucronata, whilst the close inspection of a multi-stemmed willow in the floodplain of the River Thame at SU580937 yielded an impressive 15 epiphytes on one tree, including more S. latifolia and S. papillosa.

Chinnor Bryophytes

Our 4th bryophyte excursion of the 2019/20 season was to the old Chinnor Quarry at SP7500. Four bryologists were in attendance on what was a pretty grey and damp Sunday (12/01/2020). Despite this, things got off to a good start in the small, recently planted woodland adjacent to the car park at SP757004. Earlier in the year on a vascular plant survey this woodland had offered up some gems, including the White Helleborine (Cephalanthera damasonium), and it didn't disappoint now either. David quickly found Microbryum davallianum on crumbling soil along the central path through the woodland, alongside some infertile Aloina (most probably aloides judging by the amount of this species that we later saw in the old quarry).

Microbryum davallianum

Crossing over into the old quarry, now surrounded on one side by a housing estate, Aloina aloides (confirmed microscopically) was quickly picked up in the somewhat surreal damp chalky moonscape that dominates this area.

Aloina aloides

The Chinnor moonscape (ok, there was some grass as well...)

After inspecting what seemed like acres of Didymodon fallax, we picked up a few more unusual species, Campyliadelphus chrysophyllus for one. This is a species that is well-known to haunt the floors of damp chalk quarries, but it was the first time that any of us had seen it in Oxfordshire.

Campyliadelphus chrysophyllus at Chinnor

One species that we did hope to refind was Leiocolea badensis, a species recorded from the Chinnor quarries once in the 1960s, but never since. We found Leiocolea turbinata, its commoner congener, quite quickly, but, unfortunately, despite collecting several candidates for checking, we failed to locate the rarer species. Other interesting species in the quarry area included Campylium protensum, Cratoneuron filicinum, and Aneura pinguis, all in the vicinity of the large pond pictured below, and all species of damp calcareous habitats.

The pond area at SP759002

After lunch, we inspected an interesting area of sandy ground forming the football pitch of the housing estate previously mentioned. This was made of soil that had presumably been brought in for the purpose, and had abundant Phascum cuspidatum and occasional Pohlia annotina, the latter a species that has only four other records for Oxfordshire, and was last recorded for the vice-county in 1991. The rest of the excursion was filled by recording the wooded slope rising up to the Ridgeway footpath, and then circling back to the original car park. More Microbryum was encountered in patchy roadside grassland alongside the roundabout at SP758004, as was some Brachythecium mildeanum, our first record of this species for the season. The full list follows (duplicates are those recorded in the car park wood as well as the main square):

Mosses			Liverworts
Aloina aloides s.str.	Ctenidium molluscum	Orthotrichum affine	Aneura pinguis
Amblystegium serpens	Dicranella varia	Orthotrichum affine	Cololejeunea minutissima
Barbula convoluta var. convoluta	Dicranoweisia cirrata	Orthotrichum diaphanum	Leiocolea turbinata
Barbula unguiculata	Didymodon fallax	Orthotrichum diaphanum	Metzgeria furcata
Brachythecium mildeanum	Didymodon fallax	Oxyrrhynchium hians	Radula complanata
Brachythecium rutabulum	Didymodon insulanus	Oxyrrhynchium hians
Brachythecium rutabulum	Fissidens incurvus	Phascum cuspidatum
Bryoerythrophyllum recurvirostrum	Fissidens taxifolius	Plagiomnium undulatum
Bryum argenteum	Fissidens taxifolius	Plagiomnium undulatum
Bryum capillare	Funaria hygrometrica	Pohlia annotina
Bryum capillare	Funaria hygrometrica	Pseudocrossidium hornschuchianum
Bryum dichotomum	Grimmia pulvinata	Pseudoscleropodium purum
Bryum dichotomum	Grimmia pulvinata	Rhynchostegium confertum
Bryum pseudotriquetrum	Homalothecium lutescens	Rhytidiadelphus squarrosus
Bryum rubens	Homalothecium lutescens	Schistidium crassipilum
Calliergonella cuspidata	Homalothecium sericeum	Syntrichia laevipila
Calliergonella cuspidata	Hypnum cupressiforme var. cupressiforme	Syntrichia montana
Campyliadelphus chrysophyllus	Hypnum cupressiforme var. resupinatum	Syntrichia ruralis var. ruralis
Campylium protensum	Kindbergia praelonga	Thamnobryum alopecurum
Ceratodon purpureus	Kindbergia praelonga	Tortula muralis
Cirriphyllum piliferum	Leptodictyum riparium	Tortula muralis
Cratoneuron filicinum	Microbryum davallianum	Tortula subulata
Cryphaea heteromalla	Microbryum davallianum	Zygodon viridissimus var. viridissimus

Bletchingdon Bryophytes

For our third recording trip of the season, after two consecutive trips to nature reserves, we decided to focus on the wider countryside, plumping for the village of Bletchingdon. A picturesque village in northern Oxfordshire built around a large green, adjacent to a grand manor house in a Palladian style. The village is adajcent to the Oolitic cornbrash limestone bedrock, and as such we expected good hunting for bryophytes on the many limestone walls of the village. Indeed, although mainly intending to focus on SP5018, we spent some time after arriving inspecting a fine wall along the road from the village green to the church. The wall had the fruiting feather (pleurocarpous) moss Homalothecium sericeum above fine and extensive sheets of Porella platyphylla, a liverwort that you may recall from our last trip to Watlington Hill. The wall also yielded Syntrichia virescens, among others; David picked this out from amongst the more abundant, larger, Syntrichia montana. A later check under the microscope proved him right! This is a probably under-recorded species, only recognised as British in 1959. The 1998 Flora of Oxfordshire hedged its bets by labelling it "?rare".

Fine sheets of Porella platyphylla in the morning sun.

Homalothecium sericeum in fruit at Bletchingdon.

Hurrying on from the delights of this wall (we were in fact late to our official rendezvous point!), we then focused on the churchyard of St Giles for an hour or so. This included a range of graves of different stone, aspect, angle, and shadedness, resulting in a pretty good list. The highlight of the limestone headstones being some small patches of Tortella tortuosa. A notable near miss was an infertile Aloina species from the churchyard path; sadly these little acrocarps are unidentifable (at least without molecular techniques!) from infertile material, so this record remains at the genus level. Interestingly, Aloina ambigua was recorded from Bletchingdon stone pit in 1945. The full list from the churchyard was as follows:

Aloina sp.	Orthotrichum affine
Barbula convoluta var. convoluta	Orthotrichum anomalum
Barbula convoluta var. sardoa	Oxyrrhynchium hians
Barbula unguiculata	Phascum cuspidatum
Brachythecium rutabulum	Plagiomnium undulatum
Bryum argenteum	Pseudocrossidium hornschuchianum
Bryum capillare	Pseudoscleropodium purum
Ceratodon purpureus	Rhynchostegiella tenella
Dicranella varia	Rhynchostegium confertum
Didymodon fallax	Rhynchostegium murale
Didymodon insulanus	Rhytidiadelphus squarrosus
Didymodon sinuosus	Schistidium apocarpum s.l.
Grimmia pulvinata	Thamnobryum alopecurum
Homalothecium sericeum	Tortella tortuosa
Hypnum cupressiforme	Tortula muralis
Hypnum cupressiforme var. resupinatum	Zygodon viridissimus var. viridissimus
Kindbergia praelonga	Metzgeria furcata
	Porella platyphylla

The rest of the day was spent exploring SP5018, taking in a circular walk around the parkland of Bletchingdon manor, ultimately heading back into the village along the Kirtlington road. Overall we put a together a long list for the day, including Neckera complanata and more Porella together on a large ash stool, Oxyrrhynchium speciosum on the edge of a small stream in woodland, and Syntrichia papillosa on another large ash tree. On the way back to the village a stubble field was also worked over, although this yielded a fairly typical assemblage of Barbula unguiculata, Phascum cuspidatum, Oxyrrhynchium hians, and the tuberous Bryum, B. klinggraeffii. Both assemblages of fields in the calcareous parts of south-east Britain (see Preston et al., 2010 [complete the "captcha" image text to access the paper]).

Neckera complanata growing on a wall with H. sericeum at Bletchingon Park

Finally, arriving back into Bletchingdon, we spent some time grubbing around for urban ruderal species, adding Brachythecium albicans and Tortula modica from some unusually sandy soil behind kerbstones, followed by the classic wet tarmac species Didymodon nicholsonii, Ceratodon purpureus, Bryum dichotomum and Orthotrichum anomalum from a playground. A pre-Christmas pint soon followed! The full list from the wider 1km square was as follows:

Amblystegium serpens	Grimmia pulvinata	Rhynchostegium confertum
Barbula unguiculata	Homalothecium sericeum	Syntrichia laevipila
Brachythecium albicans	Hypnum cupressiforme	Syntrichia montana
Brachythecium rutabulum	Hypnum cupressiforme var. cupressiforme	Syntrichia papillosa
Bryum argenteum	Hypnum cupressiforme var. resupinatum	Syntrichia ruralis var. ruralis
Bryum capillare	Isothecium myosuroides	Thamnobryum alopecurum
Bryum dichotomum	Kindbergia praelonga	Tortula modica
Bryum klinggraeffii	Leskea polycarpa	Tortula muralis
Bryum moravicum	Neckera complanata	Tortula truncata
Ceratodon purpureus	Orthotrichum affine	Ulota bruchii
Cryphaea heteromalla	Orthotrichum anomalum	Zygodon conoideus
Didymodon insulanus	Orthotrichum diaphanum	Frullania dilatata
Didymodon nicholsonii	Orthotrichum lyellii	Lophocolea bidentata
Didymodon sinuosus	Oxyrrhynchium hians	Metzgeria furcata
Didymodon vinealis	Oxyrrhynchium speciosum	Porella platyphylla
Fissidens incurvus	Phascum cuspidatum	Radula complanata
Fissidens taxifolius	Platyhypnidium riparioides

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Bryophytes of Watlington Hill

Watlington Hill is a well-known site for chalk grassland bryophytes, although, despite this, relatively few recent records are available for the area (no post-2000 records for the main monad, SU7093, are in the BBS database or on the NBN Atlas for example). However, historically the site has been well searched. Ron Porley, when at English Nature, completed a thorough survey of the Hill in the early 90s, as a part of his work on the chalk grassland of the Chilterns. Porley found the Watlington & Pyrton Hill area to be the richest of the 13 sites he surveyed in terms of chalk grassland specialist bryophytes, recording 46 of his 69 such designated species at the site (although the site was also one of the largest in terms of the area of chalk grassland, estimated at 50.9 ha at that point).

Therefore it was with high expectations that five bryologists assembled at Watlington Hill for the second excursion of the Oxfordshire mossing season (1st Dec. 2019). A number of our group were relatively new to bryophytes, so we started in the woods surrounding the main carpark, demonstrating some of the commoner feather-mosses (pleurocarps) and epiphytes (tree-dwelling bryophytes).

A gentle start to the day!

Our list rapidly swelled, with a number of epiphytes available to demonstrate, including the mosses Orthotrichum stramineum, O. affine, O. diaphanum, Cryphaea heteromalla, and Zygodon conoideus var. conoideus, and the liverworts, Radula complanata, Frullania dilatata, Metzgeria furcata and M. violacea. When I was learning bryophytes around Sheffield in the late 2000s, this would have been considered an impressive haul indeed (at that point, these species were still recolonising after having been previously eradicated from the area due to acidic pollution)! Soon after, David discovered a fallen ash with a superabundance of another epiphyte, Orthotrichum lyellii, a distinctive moss with many brown gemmae covering its leaves. Whilst we often find this on our outings, we normally only find small tufts on standing trees: no doubt our impression is biased by our vision and reach, as this supine ash demonstrated that this species can clearly become locally abundant further up trees!

Orthotrichum lyellii (middle distance) abundant on fallen ash

O. lyellii close-up, showing the brown gemmae

Progressing through the woodland along a track along the edge of the wood, a number of species typical of soil or tree roots were found. The most handsome probably being the liverwort Porella platyphylla, which tends to be found on old limestone walls, graves, hard chalky soils, and the roots of trees on such soils in the Oxfordshire district.

Porella platyphylla on beech root at Watlington.

After lunch, we emerged into chalk grassland, and most of the rest of the excursion was spent crawling around this habitat, as proven by Joshua's tweet below...

Amazing Spiderman bryologists! @sacrevert and #DavidMorris.@BBSbryology @sambbryo
Beautiful landscape too! pic.twitter.com/ilY4NGXaK8

— Joshua Ajowele (@JAjowele) December 3, 2019

A trampled path through the grassland provided us with our first chalk grassland specialists, including Microbryum curvicolle (no photo, but a nice illustration can be found here). Fissidens dubius, Weissia longifolia var. angustifolia, and the tiny stone-covering Seligeria calycina were all also found along this track or in grassland nearby, as well as several other currently infertile small cushion mosses (acrocarps). The idea of returning in the early spring was floated at this point!

Moving into a larger area of grassland on an east-facing slope, David soon located Entodon concinnus, a lovely species normally indicative of rich turf.

Entodon concinnus at Watlington

Sure enough, other species such as Trichostomum crispulum, Hypnum lacunosum and Ctenidium molluscum were all nearby. Mounting the brow of the hill, we encountered the more acid clay-with-flints that often heralds local concentrations of calcifugous species (i.e. those that prefer acid soils). Dicranum scoparium, Polytrichum juniperinum, and P. piliferum were all found in this area.

On circling back to the car park, more rich calcareous turf was found on west and north-west facing slopes, including Ditrichum gracile, Campylium protensum, Plagiomnium affine, Rhytidiadelphus triquetrus, and Brachythecium glareosum. The last was confirmed microscopically back at home, as was Brachythecium salebrosum found in the wood near the carpark at the start of the day. Other species confirmed microscopically included Bryum klinggraeffii, B. ruderale, B. rubens, Fissidens viridulus and Zygodon viridissimus. There were a number of Watlington rarities that we didn't find, but these will hopefully be targeted on the 2020 spring visit previously mentioned! The full list from the day is below.

Ditrichum gracile in chalk grassland at Watlington.

Amblystegium serpens	Fissidens dubius	Polytrichum piliferum
Barbula convoluta var. convoluta	Fissidens incurvus	Pseudoscleropodium purum
Barbula unguiculata	Fissidens taxifolius	Rhynchostegium confertum
Brachytheciastrum velutinum	Fissidens viridulus	Rhytidiadelphus squarrosus
Brachythecium glareosum	Homalothecium lutescens	Rhytidiadelphus triquetrus
Brachythecium rutabulum	Homalothecium sericeum	Seligeria calycina
Brachythecium salebrosum	Hypnum cupressiforme var. cupressiforme	Syntrichia laevipila
Bryum capillare	Hypnum cupressiforme var. lacunosum	Syntrichia ruralis var. ruralis
Bryum klinggraeffii	Hypnum cupressiforme var. resupinatum	Thuidium tamariscinum
Bryum rubens	Isothecium myosuroides	Trichostomum crispulum
Bryum ruderale	Kindbergia praelonga	Ulota bruchii
Calliergonella cuspidata	Leptobryum pyriforme	Weissia brachycarpa var. obliqua
Campylium protensum	Microbryum curvicollum	Weissia longifolia var. angustifolia
Campylopus introflexus	Mnium hornum	Zygodon conoideus var. conoideus
Ceratodon purpureus	Orthotrichum affine	Zygodon viridissimus var. viridissimus
Cryphaea heteromalla	Orthotrichum diaphanum
Ctenidium molluscum	Orthotrichum lyellii	Cephalozia bicuspidata
Dicranella varia	Orthotrichum stramineum	Frullania dilatata
Dicranum scoparium	Oxyrrhynchium hians	Lophocolea heterophylla
Didymodon fallax	Plagiomnium affine	Metzgeria furcata
Ditrichum gracile	Plagiomnium undulatum	Metzgeria violacea
Entodon coccinus	Plagiothecium nemorale	Porella platyphylla
Eurhynchium striatum	Polytrichum juniperinum	Radula complanata

Bryophyte season kicks off in the Lye Valley

In a joint effort to be more organised and transparent, this season all our meetings are on the blog calendar! We will be emailing around the details of meetings a few days in advance, if you are on David's botanical mailing list, you'll get them. If not, get in touch!

Our first meeting of the season was to the eastern suburbs of Oxford to visit the Lye Valley (SP5405), incorporating the Local Nature Reserve of the same name. This site used to be known as Bullingdon Bog, and as such is something of a locus classicus for Oxonian botany. It was, for example, the site where L'Obel made the first record of Parnassia palustris for Britain; it was recorded by Sibthorp and Boswell, and featured in early ecological work on calcareous fens by Roy Clapham (later lead author of the primary British Flora in use from 1958 up to the early 90s, when it was superceded by Stace).

A view along the Lye Valley LNR. (O.L Pescott, CC0).

It seems that we are lucky to still have the site in the reasonable condition that it is in. Eustace Jones in the early 1950s commented that "Bullingdon Bog which must once have been an ideal example of a calcareous valley bog, is now a disturbed fragment lying in the middle of an Oxford housing estate, and obviously cannot survive much longer." Although the site was scrubbed over in recent years, and the valley sides slumping due to scouring of the valley bottom by a storm drain outflow directed along the stream, excellent management work has taken place in recent years, and is gradually restoring the valley mire to its former glories (thanks to David Morris for this information).

Bryologists assemble! (O.L. Pescott, CC0).

But to the bryophytes! We dropped into the valley from Coverley Road, recording the woodland and along the stream before the beginning of the LNR proper. Many common species were quickly found, including Tortula subulata on friable soil, and Rhyncostegiella tenella on stone. Along the stream the thallose liverworts Lunularia cruciata and Pellia endiviifolia were growing in close association at the bottom of a concrete embankment. An odd amblystegioid growth was also scraped from concrete, which, under the microscope, seemed to match descriptions of the coastal variety of Amblystegium serpens var. salinum. This, however, would be an odd turn-up for Oxford, and must await confirmation from the BBS Recorder for Mosses! Subsequently an old Hawthorn turned up a rich crop of epiphytes, including the ever expanding (and beautiful) species Orthotrichum stramineum and Syntrichia papillosa. An uncertain Ulota was later checked at home, but turned out to be the commonest taxon (at least locally) U. bruchii.

After lunch the reserve proper was tackled, and a new list was begun to ensure that records made would be traceable directly to the LNR. Many epiphytes and common species were again quickly added, including a number that chose to grow on the synthetic wood of the reserve boardwalk (Syntrichia latifolia, S. montana, S. virescens, Orthotrichum affine, O. diaphanum, among others). Next was the fen proper, and many of our expected species began to accumulate (Plagiomnium elatum, Cratoneuron filicinum, Palustriella commutata, P. falcata, Campylium stellatum, Fissidens adianthoides etc.) All previously known from the mire, but all lovely to see thriving. The curious epiphyte Platygyrium repens was also found on a pollarded willow along the stream. Deciduous branchlets of very fine leaves give this species a fuzzy appearance in the field.

Platygyrium repens at Lye Valley. (O. Pescott, CC-BY).

Some known species we failed to refind (e.g. we did not relocate Drepanocladus revolvens or Climacium dendroides), but many other species were added to the site list. A productive day, and a good start to the season.

The list of unique species seen was as follows:

?Amblystegium serpens var. salinum	Platyhypnidium riparioides	Brachythecium rivulare
Amblystegium serpens	Rhynchostegiella tenella	Bryum pseudotriquetrum
Barbula convoluta var. convoluta	Rhynchostegium confertum	Calliergonella cuspidata
Barbula convoluta var. sardoa	Schistidium apocarpum s.l.	Campylium stellatum s.str.
Brachythecium rutabulum	Syntrichia laevipila	Cirriphyllum piliferum
Bryum capillare	Syntrichia papillosa	Ctenidium molluscum
Bryum moravicum	Tortula muralis	Dicranoweisia cirrata
Cratoneuron filicinum	Tortula subulata	Didymodon fallax
Cryphaea heteromalla	Ulota bruchii	Fissidens adianthoides
Didymodon sinuosus	Zygodon conoideus var. conoideus	Fissidens incurvus
Fissidens bryoides	Cololejeunea minutissima	Orthotrichum lyellii
Fissidens taxifolius	Frullania dilatata	Palustriella commutata s.str.
Homalothecium sericeum	Lophocolea heterophylla	Plagiomnium elatum
Hypnum cupressiforme var. cupressiforme	Lunularia cruciata	Plagiomnium undulatum
Hypnum cupressiforme var. resupinatum	Metzgeria furcata	Syntrichia latifolia
Kindbergia praelonga	Metzgeria violacea	Syntrichia montana
Orthotrichum affine	Pellia endiviifolia	Syntrichia virescens
Orthotrichum diaphanum	Radula complanata	Thamnobryum alopecurum
Orthotrichum stramineum	Platygyrium repens	Cephalozia bicuspidata
Oxyrrhynchium hians Oxyrrhynchium schleicheri	Palustriella falcata	Lophocolea bidentata

Beacon Hill bryophytes

Beacon Hill, part of the Aston Rowant National Nature Reserve, was the latest destination for the bryophilic element of the Oxfordshire Botany Group (28/01/2018). Three members assembled for a bryological recording session around the chalk grassland and woods of the hill (SU7296 & SU7297), a location that has not been thoroughly surveyed for bryophytes since Ron Porley's study of Chiltern chalk grasslands in the mid-1990s. We admittedly had a fairly easy-going recording session, and so I don't think we would claim that we surveyed the site anywhere near as intensively as Ron, but we recorded 53 species (67 records) across two monads, and refound a few of the characteristic species noted by Porley, as well as some species which appear to be new for the Hill.

Looking across to Aston Rowant from Beacon Hill.

Fissidens dubius

Focusing first on the west-facing slope around SU728968, we quickly picked up a slew of typical chalk grassland species, including Homalothecium lutescens, Fissidens dubius, Plagiomnium affine, and Weissia longifolia. Here we also found our first plants of Rhodobryum roseum, a particularly large and handsome moss that tends to be indicative of habitats that are of importance for nature conservation (due to its requirement for an open, low nutrient sward), and was unfortunately one of the species included in the "decreasing generally" category of Mark Hill & Chris Preston in their analysis of change in the recent Atlas of British and Irish Bryophytes.

Rhodobryum roseum

Rhodobryum in a typical anthill setting

Later on, in a "hollow way" lane cutting down the west-facing escarpment we recorded a good number of epiphytes, most new for the site, including two attractive Neckera species, N. complanata (pictured) and N. crispa. Here we also found a number of more weedy species existing on the risers and treads of wooden stairs installed for easier access, including Orthotrichum anomalum, Campylopus introflexus, Barbula sardoa, B. unguiculata, and Homalothecium sericium.

Neckera complanata

After lunch, we were back on higher-quality ground, inspecting the open expanses of grassland on the plateau of the hill, around SU727971. Here, after some patient hound dog style searching, we were rewarded with a cluster of rarer chalk grassland pleurocarps. These included Campylium protensum, Entodon cocinnus, and Hypnum cupressiforme var. lacunosum. The first of these has apparently not been reported for Beacon Hill, and is rare in chalk grassland in Oxfordshire; E. cocinnus is known from Beacon Hill, but has not been reported recently, at least according to records available from the British Bryological Society and the NBN.

Campylium protensum

Entodon cocinnus

The full list of species for the day is given below. Another visit will certainly be in order, as there are a number of nationally scarce bryophytes found by Porley that we didn't manage to rediscover.

Liverworts	Fissidens dubius	Zygodon conoideus var. conoideus	Plagiomnium undulatum	Brachythecium rutabulum	Entodon concinnus
Metzgeria furcata	Fissidens adianthoides	Orthotrichum affine	Campylium protensum	Brachythecium salebrosum	Cryphaea heteromalla
Radula complanata	Dicranum scoparium	Orthotrichum anomalum	Amblystegium serpens	Homalothecium sericeum	Neckera crispa
Frullania dilatata	Campylopus introflexus	Orthotrichum diaphanum	Thuidium tamariscinum	Homalothecium lutescens	Neckera complanata
Lophocolea bidentata	Weissia longifolia	Bryum pallens	Pseudoscleropodium purum	Calliergonella cuspidata
Mosses	Barbula convoluta var. sardoa	Bryum capillare	Eurhynchium striatum	Hypnum cupressiforme var. cupressiforme
Seligeria calycina	Barbula unguiculata	Bryum pseudotriquetrum	Rhynchostegium confertum	Hypnum cupressiforme var. lacunosum
Fissidens viridulus	Didymodon vinealis	Bryum dichotomum	Oxyrrhynchium hians	Hypnum cupressiforme var. resupinatum
Fissidens incurvus	Syntrichia ruralis var. ruralis	Rhodobryum roseum	Oxyrrhynchium schleicheri	Ctenidium molluscum
Fissidens taxifolius	Zygodon viridissimus var. viridissimus	Plagiomnium affine	Kindbergia praelonga	Rhytidiadelphus squarrosus

Hinksey Heights Bryophytes

Botanists enjoying a coffee break in the wood along the valley

Sunday was another winter outing for local botanists, this time on the Hinksey Heights south of Oxford and better attended than the last. Hinksey is in vice county 22 (Berkshire) meaning a day off recording vascular plants for me, but the meeting was focused on bryophytes anyway. The main interest was one of a series of long narrow valleys draining north off the heights, fed by calcareous groundwater emanating from the limestone along the valley sides. There is peat in the upper part of the valley, and it was once an open fen rich in plants such as grass-of-Parnassus but now mostly covered in willow and reed.

The valley is a nature reserve and can be reached from the Hinksey Heights Golf Club via a footpath and board walk leading north-west from the car park (the temptation to botanise which was resisted). The valley opens out at the entrance near its bottom where there are fabulous views of Oxford and its encircling hills to the north and east. The southern slope here supported the only area of Juncus subnodulosus (blunt-flowered rush) fen we came across, but it was rather overgrown.

The stream tumbling over its tufa weirs

This is where we set to bryologising, and as there were a few new-comers to the subject we could share the revelation that is the tiny world of bryophytes, with ample demonstration material provided by the several common species growing on the accumulated fen litter. The only fen moss we found, however, was a scrap of Bryum pseudotriquetrum. The stream within the woodland in the valley bottom had me fantasising of Eucladium and Gymnostomum species, with its spectacular tufa weirs (or barrage tufa) and drifts of petrified leaves and twigs. Tufa is formed where limey waters precipitate calcite (the principle calcium carbonate mineral) onto lower plants and debris, encasing them in stone, and has a specialist bryophyte flora adapted to this highly alkaline environment. The bryophyte flora, however, was rather dull, most surfaces being covered in the pleurocarp Cratnoneuron filicinum, or the thallose liverworts Conocephalum conicum and Pellia endiviifolia. This suite of species followed us up the valley, dominating the weirs, dripping banks of the stream and springs.

The peaty springs higher up were a little richer, but mostly covered in wefts of the common mosses Plagiomnium affine and P. undulatum. Exceptionally, however, and the highlight of the meeting, both species were producing sporophytes, which for P. affine is a very rare occurrence. Most species of Plagiomnium are dioecious (sexes on separate plants) and are shy to produce sporophytes — the only currently known record of P. affine in fruit in Oxfordshire or Berkshire is from nearby Bagley Wood, found by Watson many decades ago.

Fruiting Plagiomnium affine growing with Cratoneuron filicinum in a tufa spring

Like the two Plagiomnium species, most of the mosses and liverworts we recorded were general calcareous woodland plants rather than specialists of wet woodland or fens. We recorded a number of epiphytes such as the increasingly common Orthotrichum pulchellum and O. stramineum, as well as the uncommon and Brachythecium salebrosum growing on an elder. Altogether we recorded 9 liverwort and 38 moss species, but with a few specimens yet to be examined this is not the final tally. Thanks to everyone for an enjoyable meeting!

Brachythecium salbrosum growing on elder (left). The meeting was too early for the pretty capsules of Orthotrichum stramineum (right, April, Blenheim Park) but old dry capsules are distinctively red-brown and flask-shaped.