Take a look at this beautiful boulevard that’s right on our doorstep

FAIR MILE is a sumptuous entrance into Henley by road.

After passing through classic beech woods downhill from Bix, the driver or cyclist enters this broad straight avenue and what a sight it is — a marvel with two well-spaced lines of lime and turkey oak trees to either side.

A largely unbroken old brick and flint wall extends most of the way with the occasional gap on the east side which I guess once marked a boundary of Henley Park that sits between Great Hill and the strangely named No Man’s Hill.

Heading towards Henley, this glorious entrance leads with grace and subtlety into Northfield End and then over a somewhat tricky roundabout into Bell Street.

It is beautiful, a little piece of cherished southern England.

So I was pleased to receive an invitation from Henley resident Sarah Thomas to take a stroll up and down this broad and fabulous avenue with her friend and gardener Nicholas Verge, who lives in Middle Assendon.

They are both worried about the potential detrimental effect on biodiversity to the side of the “boulevard” as there is, she informs me, a plan for extensive mowing of the vegetation along the roadside and under the trees.

Before our visit Sarah has already provided me with a list of plant species recorded by Nicholas who has, as a local enthusiast, an intimate botanical knowledge of Fair Mile. It is a comprehensive enumeration and runs to well over 100 plants, so Rosemary and I are happy to oblige to meet both and take a look.

In a way I’m not surprised that the scenic stretch is so rich in wildlife, given the beautiful, rising, nearly pristine hillsides that envelop the valley entrance into town. The seeds of plants have surely ever drifted down.

We agree to meet at Sarah’s house mid-morning and what a lovely place it is. She shows us around her tree-lined garden that has its own wild area brimming with grasses and wildflowers that include yellow rattle (Rhinanthus minor). We love it. After some welcome refreshment, we set off and follow Sarah’s car to the side of a slip road to the west of the main road some short distance from the entrance to Lambridge Wood Road.

It is a bright, sunny day and despite roaring, speeding traffic to our right (thankfully the road is some way off), I can hear a chaffinch singing its heart out.

It’s a revelation to walk under the dappled shade of the trees as we head away from town. I have never set foot here before.

Under and beyond the trees to our right a varied array of native grass species sway. In between there is a broad variety of flowers — common mallow (Malva sylvestris), pink and purple-veined, the yellow florets of smooth hawk’s-beard (Crepis capillaris), the yellow disc florets and white ray florets of oxeye daisy (Leucanthemum vulgare), purple spear thistle (Cirsium vulgare), one with a resting snail (Cepaea hortensis), hedge bindweed (Calystegia sepium) with its white trumpets, and hedge crane’s-bill (Geranium pyrenaicum) with its deeply notched pink petals, all at their pinnacle.

Rosemary spots a common greenbottle (Lucilia Caesar) on the leaf of a lime tree.

Nicholas arrives on his bicycle, dismounts and joins us. Almost immediately he indicates some lucerne (Medicago sativa), the flowers with closely packed, stalked heads a shade of lilac. The plant is also known as the crop alfalfa.

I spot some pyramidal orchids (Anacamptis pyramidalis), a good sign of the overall health of this strip of land.

As we move on, Rosemary and I try to take it all in.

After waiting for a suitable break in the racing traffic (by golly it’s fast here), the four of us cross the road gingerly to the east side and spot buck’s-horn plantain (Plantago coronopus) between the road and cycleway. Nominally a coastal plant, it is spreading inland in the South-East.

Walking northwards by the roadside we see a deep ditch to our right. Nicholas tells me that it is called the Assendon Stream, a peripatetic winterbourne originating in the Stonor Valley.

The stream’s main source is a spring in a field in the valley bottom just south of Stonor. If there is an exceptionally high amount of rainfall between autumn and spring, aquifer recharge and ponds form in the field. This happens two or three times a decade.

The hydrological character of the stream is quite complex. If the recharge season has been very wet only then will water flow from the ponds down the Assendon valley.

How far it gets depends on the amount of rainfall and the level of the water table. If this is lower than average at the start of the recharge season, then no spring will appear.

After an already high autumn water table and an exceptionally wet recharge season, additional springs appear, one in front of the Rainbow pub. Water from these springs adds to the flow. The stream can be sufficient that it can reach the Thames, entering near Phyllis Court Club. The last time this happened was in 2001 when it flowed all through summer.

The stream last flowed strongly in 2014 when it reached as far as the Lambridge Road junction with Fair Mile and drained back into the valley floor.

But back to the flowering plants. The wealth of species on the east side turns out to be even more extensive.

We find four-petalled creeping cinquefoil (Potentilla reptans), black medick (Medicago lupulina) with its tiny flowers, nipplewort (Lapsana communis), dark mullein (Verbascum nigrum), and Lady’s bedstraw (Galium verum), all five various shades of yellow.

There is also field bindweed (Convolvulus arvensis) with its funnel-shaped pink and white striped flowers, yarrow (Achillea millefolium), lesser stitchwort (stellaria graminea), both white, white clover (Trifolium repens) and plenty of red-flowered hedge woundwort (Stachys sylvatica).

Also a largish colony of fox-and-cubs (Pilosella aurantiaca), a scarce, naturalised introduction with reddish-orange florets. It is also known as orange hawkbit, which is odd as it is a form of hawkweed.

The plant is similar to mouse-ear hawkweed (Pilosella officinarum), which is also present, bearing pale-yellow florets. Halfway through our walk Rosemary and I give up counting the orchids. There must be hundreds at least.

Nicholas has recorded many other plants on this notable stretch. Cowslips (Primula veris) and primroses (Primula vulgaris) have finished flowering months back, as has bluebell (Hyacinthoides non-scripta) and dog violet (Viola canina). Cow parsley (Anthriscus sylvestris) is seeding.

Other plants have also been recorded in recent years including common spotted-orchid (Dactylorhiza fucsii), vipers-bugloss (Chium vulgare), chicory (Cichorium intybus), both blue, common comfrey (Symphytum officinale) and wood anemone (Anemone nemorosa). There are so many others.

As one would expect with so many species of grasses and wildflowers, both sides of the thoroughfare are brimming with insects from grasshoppers to marbled white butterflies (Melanargia galathea).

Two of the latter’s food plants, red fescue (Festuca rubra) and cock’s-foot (Dactylis glomerata), are both abundant here.

It has been an interesting day with great views. I loved looking up over the old wall at Fairmile Vineyard.

I do hope that the land either side of Fair Mile is treated with sensitivity. I would recommend that it be given local nature reserve status.

Do go and take a look — you won’t regret it.

vincent.ruane@hotmail.com