26 August 2012 OS Explorer 171: Chiltern Hills West
Length: All day.
This walk focussed on two plants: Chiltern Gentian Gentianella germanica in two very good colonies and Pale Toadflax Linaria repens. While the latter is rather scarce these days, it can be so common in this region that it has been dubbed “Henley toadflax”.
We parked by the Henley Football Club ground SU772817, which is towards the end of a minor road on the south edge of Henley going towards the River Thames. There are other car parks near the Thames which could also be used. Apart from the convenience for parking it provided a chance to examine the banks of the Thames for plants.
A path from the car park crossed a stream with Water Mint Mentha aquatica and Lesser Water Parsnip Berula erecta and then wide green parkland, with leaves of Aspen Populus tremula rustling even in the slightest breeze, to the towpath beside the Thames, which we followed north towards the centre of Henley.
Aspen in Thames-side park
The bank was shored up and many pleasure-boats and barges were tied up along it, while the grass is kept short, so there was not a great abundance of water plants. In the river itself we could only see masses of very long narrow leaves of what we presumed to be Unbranched Bur-reed Sparganium emersum, although there were no emergent spikes, and in one place the large submerged leaves of Yellow Water-lily Nuphar lutea. On the banks where they could get a foothold in the gaps between the metal shearing and concrete were Water Figwort Scrophularia auriculata, Purple Loosestrife Lythrum salicaria, Gipsywort Lycopus europaeus, Canadian Fleabane Conyza canadensis, Mexican Fleabane Erigeron karvinskianus, Pellitory-of the-wall Parietaria judaica, Ivy-leaved Toadflax Cymbalaria muralis, and Meadowsweet Filipendula ulmaria.
Water figwort
A pool at the side of the path away from the river had Hemlock Water-dropwort Oenanthe crocata, Drooping Sedge Carex pendula, Alder Alnus glutinosa with leaf-galls of the mite Eriophyes laevis, and a White Willow Salix alba with Poplar Bracket Oxyporus populinus at the base and younger specimens following the line of a cleft in the trunk above. Here Banded Demoiselles Calopteryx splendens sported their conspicuous wings. On the river were numerous Canada and greylag geese, coots, mute swans and mallards obviously used to be being fed, as scullers came by, perhaps preparing already for the next Olympics.
Thames looking towards Henley
After the A4130 road bridge we could only go a little further by the river, beside the Thames-side road, before private property frontage monopolised the banks. Here we turned into the town, busy on a rare sunny Sunday with holidaymakers up to the A4155, past the Brakespear brewery, opposite which we found a patch of Adherent Bristle-grass Setaria adhaerens sheltering in the shade of other plants where the pavement abutted a town-house. This presumably came from birdseed scattered here by accident.
Spike of Adherent Bristle-grass
We followed the A4155 north to the fork, where we took the A4130 north-westwards. This was only for short distance until we took the Oxfordshire Way footpath at the side of the Rupert House playing-fields and were pleased to leave the bustle and cars behind.
In the field on the left the presence of the chalk was revealed with a line of Dark Mullein Verbascum nigrum, as we went uphill into a wood. This was mostly of young trees, but the wood was presumably ancient, as an Oak Quercus robur to our right, which had survived as a boundary marker, measured 4.65 metres in girth. There was little ground cover, just some sanicle Sanicula europaea and Enchanter’s Nightshade Circaea lutetiana. On the left of the path towards the top of the wood, however, was a wood solely of Box Buxus sempervirens.
Box wood
Young box leaves
Although the trees were obviously quite old, we wondered whether they were planted in, say, Victorian times, as they border the former Deer Park associated with Henley House (just as the famous boxwoods at Chequers are part of a country estate where exotic planting is common). On the other hand, we were now in the general area of Bix, a village which gets its name from the Anglo-Saxon bixen/byxen “relating to box”, so one presumes there would have been native boxwoods in this area for many centuries. For the moment at least the boxwood seems set to survive, with young bushes having self-seeded in surrounding woodland (as they will also do from garden box-plants).
Leaving the wood the path rose to the top of the hill in the Deer Park with scattered oaks of a considerable size, a few suffering, possibly from drought, others standing as white skeletons, but even these will of course provide an important habitat for invertebrates.
Oaks in Deer Park
Fallen oak
Some of the oaks had the sticky knopper galls. More exotic plantings include Cedar of Lebanon Cedrus libani and pines.
Cedar of Lebanon
Otherwise, however, the grassland was continually sheep-grazed and quite sterile with few plants. Where the path crossed the bridleway just before Henley Park House another boundary oak measured an impressive 6.85m in girth and is therefore many centuries old. At its base was a group of Rooting-shank toadstools Xerula radicata.
We continued on the Oxfordshire Way past the house, with a tree a hundred metres off to the left with large clusters of Mistletoe Viscum album. At Dobson’s Lane we turned right up the lane and were now for a little while in Buckinghamshire. Outside Crockmore Farm on the left were a few plants of Stone Parsley Sison amomum.
Stone parsley
Opposite the stud farm a footpath comes off to the left towards Fawley Bottom. After three fields the path goes down along the edge of a wood on the steep slope. Along here are Hemp Agrimony Eupatorium cannabinum, Wild Basil Clinopodium vulgare, Marjoram Origanum vulgare and Nettle-leaved Bellflower Campanula trachelium, once again showing the influence of chalk.
Nettle-leaved bellflower
After crossing the drive to a house the woodland borders an open slope on the left, easily accessible, which is the remains of an old orchard, although few fruit trees are now evident. This is an excellent chalk grassland, however, and the dense colonies of Chiltern gentian were immediately obvious, some of the plants of prodigious size, perhaps the effect of rainy summer. (Even Father’s Day had had to be postponed – see picture!)
Fawley Bottom Orchard with Chiltern gentians
Chiltern gentian
Here also were Clustered Bellflower Campanula glomerata, Dwarf Thistle Cirsium acaule, Carline Thistle Carlina vulgaris, Common and Chalkhill Eyebrights Euphrasia nemorosa & pseudokerneri, Small Scabious Scabiosa columbaria, Quaking Grass Briza media, Dogwood Cornus sanguinea, Yellowwort Blackstonia perfoliata, Burnet-saxifrage Pimpinella saxifraga, Greater Knapweed Centaurea scabiosa, Common Milkwort Polygala vulgaris, Hairy St. John’s-wort Hypericum hirsutum, and Agrimony Agrimonia eupatoria. At the edge of the woodland at the top of the slope and further into it was Spurge Laurel Daphne laureola and, for the first time today, an extensive colony of pale or “Henley” toadflax.
Pale toadflax
At the edge of the wood we also found Round-mouthed Snail Pomatias elegans, a good indicator of undisturbed chalk grassland, and the Lapidary Snail Helicigona lapicida, with its sharp ridge around the circumference, another indicator of old chalk woodlands and now scarce in this area, among other common molluscs.
Lapidary Snail shell with Round-mouthed snails
It is always difficult to tear ourselves away from these floriferous grasslands, but we returned to the wood and continued down the path past more spurge laurel and Ploughman’s Spikenard Inula conyza. This led into a small lane where we turned left to Fawley Bottom, the hedge-banks full of nettle-leaved bellflower, although almost all of these were in seed. We turned left again at the next lane, which took us south past the bottom of the orchard, into which there is again access, although it is longer grass here and less flowery. An ancient roadside Ash Fraxinus excelsior had more poplar bracket at its base, and we passed Hedgerow Cranesbill Geranium pyrenaicum.
Poplar bracket at base of old ash
The lane runs along the bottom of a valley with beechwood on the steep slope to the right where, as well as continuing nettle-leaved bellflower, we could see Wood Barley Hordelymus europaeus, Wood Melick Melica uniflora, Violet Helleborine Epipactis violacea, the thin elongated spikes of Vervain Verbena officinalis, and Large-leaved Lime Tilia platyphyllos. There were saplings of the latter, so that it was not confined to planted trees, and perhaps it may even be native here, although rarely so in this region. Its leaves contained the galls of the mite Eriophyes exilis.
At the end of the wood we crossed the county boundary back into Oxfordshire and the hedge-banks now had lots more pale toadflax, while the wood barley continued even beyond the wood. Eventually, after enjoying this quiet and botanically rich lane, we came into the village of Middle Assendon, opposite The Rainbow pub, which could be an appropriately timed lunch spot.
The Rainbow, Middle Assendon
After a quick drink, however, we continued north up the B480 a short distance to where we could rejoin the Oxfordshire Way, which here proceeds along the little lanes to Bix Bottom and beyond. These hedgerows were not however, as flowery as that between Fawley Bottom and Middle Assendon, although we still saw plenty of hedgerow cranesbill and more pale toadflax, which is obviously still plentiful in this area, although not so close to Henley. Beyond Bix Bottom we began to see red-legged partridge quite regularly in the fields and hedges.
At a fork we took the lane to the left towards Warburg Nature Reserve, while the Oxfordshire Way continued on the right-hand lane. Warburg is run by Berks, Bucks & Oxon Wildlife Trust and, with a mix of woodland and grassland, harbours a large range of flowers, including many orchids. It is well worth a visit earlier in the summer, when many more flowers can be seen, but we were concentrating today on its colony of Chiltern gentian. The first part of the reserve that we encountered on our right was a “hanger” of beech Fagus sylvatica, Maidensgrove Scrubs, again with wood barley, although we could not find any Lesser Brome-grass Bromopsis benekenii, which is supposed to grow around here. We are finding it very difficult these days to locate any colonies of this scarce grass in this area. Further on, we passed the cottages of Pages Farm, where the walls sported more Pale Toadflax and the wood-edge more ploughman’s spikenard.
Shortly after this we came to the visitor centre, which has a good display of plants in front, a small pond with a hide for observing it and the bird-feeders beyond (we saw nuthatch and marsh tit visiting today), and a plot for arable annuals behind. We first observed Common Valerian Valeriana officinalis here, but at the top of the short flight of steps to the centre, just where we remembered seeing it nearly 40 years ago, was still Sweet Cicely Myrrhis odorata, a plant that is rare in the south, although quite common in the north of England. Its pale-flecked leaves, large black seed-pods and liquorice scent when crushed make it very easily recognisable.
Sweet cicely leaves
Sweet cicely seedpods
When we first saw it there was one plant, but now there is quite an extensive group, although it does not seem to have spread to any new location. From here we went through the car-park (more vervain) to follow one of the suggested trails named “Wildlife Walk”, a convenient way of seeing the various habitats if, as now, there is little time to explore more extensively, for it is quite a large reserve, where one can easily spend all day. Again there was plenty of nettle-leaved bellflower and vervain beside the path. Eventually the path led to a large open grassland area higher up the hill where the Chiltern gentians, as always, were making a good show, always a delight to see, although not quite as dense or vigorous as at Fawley Bottom.
Chiltern gentians, Warburg reserve
Common centaury Centaurium erythreaea and Wild Thyme Thymus drucei were still in flower, and even a little of the Rock-rose Helianthemum nummularium, whose leaves and seed-heads carpeted the ground in places. There were also plenty of salad burnet Poterium sanguisorba leaves and the strange stiffly erect, V-branched stems of Common Gromwell Lithospermum officinale, quite common here although we hardly find it anywhere else these days. In the wooded areas we could still find seed-spikes of Broad-leaved Helleborine Epipactis helleborine and violet helleborine, but we were too late to see all the grassland orchids here such as greater butterfly.
This circular walk brought us back to the car park and all that remained was to make our way back to Henley. We wanted a reasonably direct route that avoided major roads, so we returned the way we had come to Bix Bottom but there took the footpath that goes south past Bix Common. Just behind the farm at Bix Bottom was a large group of Indian balsam Impatiens balsamifera, which had obviously been cut down but was recovering well and going to be difficult to eliminate.
Looking back to Bix Bottom
The path goes up through Bushy Copse and to the A4130 at the west end of Bix. A path opposite, just to the left (there is also one just to the right) took us to a small wood where we branched off to Bix Manor Farm. Here a lane runs SE to a T-junction and Lambridge Wood opposite. We crossed to the wood where the dominant route is a bridleway which becomes a drive to a large house and goes too far north, so we had to search for the minor path which follows an old ditch and embankments and eventually follows the south edge of the wood. This emerges through a golf course, where eventually it leads by a belt of beech and lime Tilia x europea trees where, among sanicle and woodruff Galium odoratum there was more spurge laurel and many good spikes of flowering violet helleborine.
Violet helleborines on golf course
For a change, deer were obviously disinclined to reach the centre of the golf course and so the spikes were not as usual bitten off, so this makes an excellent miniature sanctuary for the plants. The path leads on into Henley where streets led to the centre and back to the river. The park beside the river was now occupied by many large picnicking groups enjoying a rare day of sun in 2012.
