Plasteurhynchium striatulum

Sunday 9th December 2018 – Tyntesfield, Bristol

Tyntesfield, a splendid Victorian mock-gothic mansion set in extensive mature grounds, was purchased by the National Trust in 2002 and is still managed as a working estate. WBG members had special permission to visit and explore the bryological interest of the estate, which had not been surveyed before.

Being keen to get started, we began recording even before we made it through the turnstiles and in trampled turf near the café Claire picked up Microbryum davallianum, with its distinctive tuberculate spores.

Many epiphytes were found in the arboretum, although the consensus seemed to be that young Orthotrichum capsules were later than usual in developing in response to the exceptional summer of 2018. A very good range of species was recorded here and elsewhere in the estate, including Orthotrichum striatum, O. tenellum and Cololejeunea minutissima.

Moving on, a strange-looking pleurocarp on limestone boulders in woodland generated much discussion, especially when it turned out to be atypical Cirriphyllum crassinervium. Growing nearby were Anomodon viticulosus, Porella platyphylla and the nationally scarce Plasteurhynchium striatulum, which is not infrequent in limestone woodland in this part of Somerset. Brachythecium mildeanum was found on the cracked concrete lining of a small lake but the masonry around the house itself yielded disappointingly little.

Our quest for a sunny lunch spot took us up onto the steep wooded slope above the house. Although the woodland lies mainly on limestone, a small outlier of quartzitic sandstone added a more acidic flavour to the bryophytes and here we recorded a number of common calcifuges, including Dicranella heteromalla, Hypnum jutlandicum and Pseudotaxiphyllum elegans.

Moving downhill again, we explored the kitchen garden and old glasshouses. Here we were delighted to find hundreds or even thousands of rosettes of Riccia sorocarpa (what is the collective noun for a mass of Riccia?) growing alongside Marchantia polymorpha var. ruderalis and Lunularia cruciata. A  Tortula-like acrocarp growing nearby turned out to be Tortula protobryoides and Gyroweisia tenuis and Bryum radiculosum were spotted on soft damp mortar of the greenhouses.

Riccia sorocarpa

Near the greenhouses

Returning to plantation woodland, we climbed up to the top of the slope, eventually reaching a play area within a stand of mature conifer plantation. Of course we were searching for Sematophyllum substrumulosum, which is now known to be quite frequent in coniferous woodland in North Somerset, and we were not disappointed. Several well-decayed fallen trees supported splendidly fertile populations, the masses of neat capsules attracting many attempts at photography. Nowellia curvifolia was also seen in the same area.

By now the light was dwindling fast and we made our way back downhill toward the exit through a small wooded combe. We couldn’t ignore a massive, well-rotted tree lying on the ground which supported a number of additional species, including Campylopus flexuosus, Lepidozia reptans and Orthodontium lineare. A leafy liverwort collected from the same tree turned out to be fertile Cephalozia connivens, more familiar to most of us from mires. A VC6 rarity (but possibly overlooked), it was a long way from its other sites on the Somerset Levels.

Sematophyllum substrumulosum

In total, 107 bryophyte taxa were recorded from Tyntesfield, a highly respectable number for the area. We are very grateful to the National Trust for permitting and facilitating our visit.

Sharon Pilkington

Tyntesfield Species recorded

 

Sunday 28th January 2018 – Hatch Hill and Combe Hill, near Street, Somerset

Arcing across the flatlands of the Somerset Levels, the Polden Hills rise from the M5 near Bridgwater and snake eastwards to the small town of Street, before turning south to Somerton. At their highest they rise to little more than 100m but in places their slopes are very steep. The range is built on relatively soft rocks – comprising alternating beds of blue lias limestone and mudstone. On the west-facing flanks of the range near Compton Dundon, these rocks are exposed on certain steep slopes as colourful horizontal bands. Gilling Down, a Somerset Wildlife Trust reserve, is possibly the largest of these.

South of Street, the ridge is clothed in planted and semi-natural woodland giving way to unimproved limestone grassland on the west-facing flanks. Much of it is managed by a conservation-led trust and is accessible to the public.

Our visit began in the free car park at Combe Hill and headed west to limestone grassland and bare rock exposures at Combe Hill. Hands and knees work quickly detected Entodon concinnus and Trichostomum crispulum, and some splendid patches of Tortula lanceola, with rich chestnut capsules. Heading downslope, more sheltered conditions favoured large mounds of Hylocomium splendens and Rhytidiadelphus triquetrus but massed reddish capsules of a smaller moss on an ant-hill quickly distracted us. These plants turned out to be the rare and very beautiful Pterygoneurum ovatum – a very good start.

Pterygoneurum ovatum

Emerging then onto the steep, limestone grassland scarp of Hatch Hill, we concentrated on searching for Leptodon smithii, a characteristic and often frequent epiphyte of the Polden Hills. Alan and Marion had not seen this species previously but were unimpressed by the tatty patch we did eventually track down on an ash tree.

Along the way we came across the rich limestone grassland and rock exposures where I’d seen Pterygoneurum papillosum in 2015. This very rare annual moss was discovered new to Britain in 2014. Its discovery prompted a flurry of checking old herbarium specimens filed as P. ovatum, which confirmed that some specimens collected from the Polden Hills were in fact P. papillosum. Substantial populations were then confirmed in limestone grassland in the Poldens, which remains the British stronghold for this species.

Limestone grassland habitat of P. papillosum, beatifully grazed by rare breeds sheep.

Where ledges of blue lias are exposed in the grassland, thin, sheep-poached clays overlie them and this is the favoured habitat of P. papillosum. We quickly found some plants, minute but easy to tell with a hand-lens due to the concave leaves with short hair-point and flaps (lamellae) overlying the nerve.

Other species of interest in this grassland included Thuidium assimile and Didymodon acutus, its dark brown shoots with erect, sharp-tipped leaves setting it apart from the much commoner D. fallax.

We took the easy path back across the top of the scarp to return to our cars. Along the way we stopped to look at epiphytes on some lovely and very majestic sprawling hazels on what appeared to be an old boundary bank of soil and limestone. On this we found a population of Plasteurhynchium striatulum, unexpected so far from its classic hard limestone Mendip haunts. We also found beech trees with masses of Cololejeunea minutissima and the dainty plants of Orthotrichum pulchellum.

Sharon Pilkington