BOX HILL: THE COMMON FLOWERS OF CHALK
THE BEST known and the finest place to begin a survey of limestone flowers is Box Hill in Surrey. Thousands of people toil up its steep chalky slopes every summer week-end and most of them pause to admire its plants. To almost every Londoner it has provided a pleasant introduction to the downland flora. Its riches and beauty are also known to visitors from all parts of the country. Fortunately for botanists the multitude are conservative in their habits, and few of them wander far from the spur which leads from the railway station to the tea-places and view-points. Solitude and a profusion of flowers can be found in the less frequented valleys even on the busiest Bank Holiday. In spite of the toll taken by visitors, Box Hill remains as good a place for plant-hunting as it was when I first knew it over 40 years ago.
The National Trust owns the hill and some of the adjacent country, and under their management it should remain in its unspoilt state. The Juniper Hall Field Centre of the Field Studies Council provides facilities for studying the natural history of the district. Students are accommodated right at the foot of Box Hill in an ideal situation, and people from all parts of England attend courses at all seasons of the year and see one of our best examples of a chalk flora.
For these reasons Box Hill has been chosen for rather more detailed treatment than it is possible to give to the other places described in this book. In this chapter the reader will be introduced to flowers which will in most cases be referred to in connection with other parts of the British Isles. In the next there will be an account of simple ecological observations of general application.
The most prominent features of the flora of the hill are the trees and shrubs which provide a patchwork of soft and charming colours throughout the year. The Box, Buxus sempervirens, with its tough dark evergreen leaves, is conspicuous in all seasons. It covers the almost precipitous slope above the Mole with a dense grove under which very few herbs can grow (Plate IIIa). It has given its name to the hill which must be one of the best-known in England. In a lease dated 25 August, 16021 the tenant covenanted to “use his best endeavours for preserving the Yew, Box, and all other trees …” and to account half-yearly for what had been sold. Six years later the receipt for Box-trees cut down upon the Sheep Walk on the Hill amounted to £50. In 1712 it was stated that the value of those felled within the preceding few years was as much as £3,000. As a native in Britain the tree is extremely local and restricted to very calcareous soils. At Box Hill it is at its best.
But in spring and summer, apart from the slope just mentioned which the thick, snaky stems of the Box dominate, other trees are more conspicuous. Of these, the finest contrast is between the very dark green (almost black from a distance) of the Yew, Taxus baccata, and the silvery foliage of the Whitebeam, Sorbus aria. The first is a conifer which shows no apparent morphological variation although it grows in practically all the chalk and limestone areas in Britain. Cattle are often poisoned by the foliage and the seeds also contain the dangerous alkaloid taxine, but the scarlet fleshy cups known as arils which envelop them are freely and eagerly eaten by birds. Very often the shoots end in a little cone-shaped tuft of leaves united together which encloses a gall with the larvae of a dipterous insect (Taxomyia taxi).
The Whitebeam is a much more variable tree and a whole range of different leaf-shapes may be found within a short distance. In the north and west of England, in Wales, Scotland and in Ireland, it is mostly replaced by allied species which will be discussed later. The white appearance so conspicuous at a distance is due to a snowy felt on the under-surface of the leaves. It is a handsome tree throughout the warmer months. From early May onwards the silvery appearance of the young leaves is very beautiful. Later in that month, in favourable seasons, it is covered with heads of sickly-smelling white flowers and these are succeeded by bright-red fruits in autumn. Finally the leaves drop off to form a white carpet on the ground. The word “beam” is an Anglo-Saxon term for tree akin to the German Baum, so “Whitebeam tree” is a pleonasm.
Although it is not confined to calcareous soils most of our native Beech, Fagus sylvatica, is to be found on the chalk of south-eastern England. Its essential requirement is good drainage and it often forms “hangers” on the shallow soils of the escarpments. Nevertheless the finest woods are often—as at Box Hill and on the Chilterns—to be seen on the deeper earth of the Clay-with-Flints. Gilbert White referred to the Beech as “The most lovely of all forest trees,” and I think he was right. When walking through one of these woods I always have a feeling that I am in a cathedral. The smooth fluted trunks branching out in curved vaulting, with the subdued light and coolness on hot summer days due to the close canopy overhead, all contribute to this impression. It is obvious to the eye that relatively little light penetrates the foliage, and this is probably the main reason why so few flowers grow on the thick layers of reddish-brown old leaves which accumulate on the ground.
The next two very characteristic trees of calcareous soils are less abundant at Box Hill than they are in the north and west. The Ash, Fraxinus excelsior, is recognised in summer by the divided (compound) leaves which have about four pairs of leaflets with an odd one at the end. Just as the Beech is easily known in the winter by its long tapering light-brown buds, so the Ash is recognised by short, stout, sooty buds on olive-green twigs which are flattened in a characteristic manner. The stalk of the leaves has a curious furrow which collects rain-water and this may sometimes be absorbed. Flowers appear before the foliage as dense purplish clusters. They are followed by the fruits, known as “keys” (Plate XXIIIa), which remain on the trees throughout the winter and then spin away in the wind to fall some distance away. It has been shown by a German botanist1 that the Ash trees of dry calcareous soils, the “lime-ashes,” belong to a different physiological race from those of marshes. The descendants of the former are satisfied with less moisture and flourish under drier conditions, so each race is adapted to its own type of habitat. Apparently their external appearance is exactly the same.
Wych Elm, Ulmus glabra, seldom grows to its full height of 60 feet or so on the chalk downs. The leaves are large (3–5 in. long), rough, and very unequal at the base, so that the larger side extends farther down the stalk. In early May in some years (1948 was a good one) the bunches of bright green fruits are produced abundantly and the tree then looks as though it is covered with delightfully pale foliage.
White Birch, Betula pendula, occurs occasionally on the chalk, though it is much more plentiful on the Clay-with-Flints. The closely allied Downy or Common Birch, B. pubescens, is not always easy to distinguish in the south of England although the characters given in the floras seem straightforward enough on paper. The difficulty is partly (perhaps mainly) due to hybridisation. In Yorkshire it is found on limestone but I do not remember it on chalk in the south. Scots Pine, Pinus sylvestris, is to be seen at intervals along the steep face of the North Downs on the shallowest of chalk soils. Although originally planted it has a tendency to extend its ground from seed. It shows to advantage against the skyline (cf. Plate 28). Small trees of the Common Oak, Quercus robur, are to be seen here and there on Box Hill, but its deep roots have no opportunity of full development on shallow chalk soils—it is more characteristic of the damper clay soils such as those of the Weald. Sycamore, Acer pseudo-platanus, is fairly plentiful in places. It is not a native tree but spreads rapidly by means of its winged fruits and grows freely from seed on calcareous soils. The indigenous Field Maple, Acer campestre, with foliage which turns a lovely golden yellow in the autumn, is plentiful all over the downs but especially in hedgerows.
Three shrubs, Dogwood, Thelycrania sanguinea, Privet, Ligustrum vulgare, and Wayfaring Tree, Viburnum lantana, often grow together. If all are present, and in quantity, as is frequently the case on the North Downs, it is almost certain that the soil is highly calcareous. Dogwood (Plate 8) is always easy to recognise by the reddish colour of the twigs, to which the second part of the scientific name refers. In the winter, after the leaves have fallen, this is often so noticeable that a whole thicket of the shrub will show up red from a distance. In autumn the foliage turns purple-red. Privet is half-evergreen—the leaves are renewed each spring but some of them remain on the shrub throughout the winter.
The Wayfaring Tree (Plate 9a and b) has always been a favourite with me. To call it a tree is something of a misnomer, for although it can grow to a height of about 15 feet it is commonly very much shorter. It is the only British shrub with naked buds; i.e., the flower and leaf buds have no hard protective scales but are merely covered with a pair of folded leaves clothed with felt, which is sufficient to preserve them from damage during the winter. Flower buds form during the summer and may be seen well advanced long before the foliage drops. As the white blossoms are collected into heads at the ends of the shoots, the display during the short flowering season at the end of April and beginning of May is very fine. On Box Hill I have seen flowers produced on young plants only about two feet tall, giving the impression that the bloom is out of all proportion to the size. The fruits are at first red, turning black later, so that in early autumn many of the clusters are made up of a mixture of both colours. The leaves of the Wayfaring Tree are broad and wrinkled, and grow in pairs opposite to one another on the stem. They are covered with a felt of dense star-like hairs which unfortunately collect the dust when it grows on roadsides (as by the “Zig-zag” up Box Hill) where, as a result, the bush sometimes looks greyish-white in midsummer.
Another very common shrub on the chalk downs is the Hawthorn, Crataegus monogyna, which grows there just as freely as it does on most other soils. On Box Hill it is the host of a small race of Mistletoe, Viscum album, which is less than half the size of the same species parasitic on Apple and Poplar elsewhere. Juniper, Juniperus communis, is a much more characteristic shrub of calcareous soils though local on these hills. It is a conifer well able to resist wind, and on the exposed escarpment it often provides shelter for young plants of other species of shrub and tree. The “berries” take several seasons to mature and may often be seen in several stages—green, pale and dark blue, and finally black—on the same bush. On the slopes of Box Hill towards the east (and elsewhere) large numbers of Juniper may be seen in a dead and dying condition, but the reason for this is not yet fully understood. Young seedlings are rare, and it is possible that intense grazing by rabbits prevents regeneration of this long-lived shrub and that the old ones are simply dying of old age without a fresh supply of younger ones to take their place.
Roses are abundant on calcareous soils and the Box Hill district is an excellent area in which to commence their study. In addition to the well-known Dog Rose, Rosa canina, in many forms, Field Rose, Rosa arvensis, and other species equally or more common on other soils, there are two which are specially associated with the chalk. The best known of these is Sweetbriar, R. rubiginosa, a low-growing erect shrub with small blunt roundish leaflets covered thickly with scented glands underneath. The sepals remain on the top of the fruit until it reddens and often stand bolt upright to form an attractive crown. In addition there is the False Sweetbriar, Rosa micrantha, which in most downland areas is more common. This is a larger, more sprawling bush with usually narrower leaflets with fewer glands and with a less pronounced scent.
Spindle Tree, Euonymus europaeus, is one of the most sought-after chalk shrubs by those who gather autumn fruits for decoration. At all times of the year it may be recognised by the smooth, green, four-angled twigs. The small green flowers are inconspicuous, but the plant attracts attention in the fall from all country ramblers. The leaves turn a brilliant reddish hue, and the pink fruits split open into four lobes to expose the bright orange covering to the white seeds buried within—one of the most striking colour contrasts to be seen in nature.
At the same season Traveller’s Joy, Clematis vitalba (Plate 1), is an important element in the Box Hill colour scheme. It is one of the best indicators of calcareous soils in the south of England, and I have often amused myself on train journeys by noticing how accurately its presence or absence marked changes in the geology. Its rope-like stems, resembling those of tropical lianas, festoon hedgerows and sprawl over trees on the edges of woods. Their bark splits away in long narrow shreds. The abundance of white flowers produced is attractive enough, but it is the mass of silvery fruits with their persistent styles, lasting well on into the winter, which are best known. These give the plant its alternative name of Old Man’s Beard.
The plants discussed so far have been trees and shrubs—the conspicuous features which individually make substantial contributions to the scenery. But the smaller flowers growing in the short, dense turf of the slopes are more characteristic of downland and collectively are responsible for much of the joy and beauty of Box Hill. In March I have seen large areas of the grassland so coloured with the blooms of the Hairy Violet, Viola hirta, that the whole hillside looked blue from a distance. These showy early blossoms appear before the leaves have fully expanded and set very little seed. A couple of months later, hidden away near the base of the long-stalked summer leaves, flowers of another kind are to be found setting seed in abundance. These are like little swollen fleshy buds with tiny malformed and often pink petals; they never open and are self-fertilised. The fruits rest on or near the surface of the ground, and thanks to the attraction of an oily body attached to each of the whitish seeds, ants carry the latter away from the parent plant and thus help it to colonize fresh ground.
On Box Hill the flowers of the Hairy Violet vary very greatly in size and colour but it is easily recognised as a tufted plant with hairy, rather pointed leaves with spreading hairs on their stalks. But these characters will not serve to differentiate it from the closely allied Chalk Violet, Viola calcarea, which is a rarity found here and in a few other widely scattered places on the chalk and limestone. This is smaller with narrower petals, of which the four uppermost are arranged in the form of a St. Andrew’s Cross, and with such a tiny conical spur that it is sometimes almost imperceptible. In their extreme forms the two plants are very distinct but they are connected by many intermediates. Some botanists (including myself) incline to the view that the Chalk Violet is really only a late-flowering (semi-cleistogamous) state of the Hairy Violet. This is supported by the fact that it does not flower until May, varies a great deal in numbers in different seasons, and that the flowers are a sort of half-way stage between the large spring flowers of the commoner species and its summer flowers described above.
The Sweet-scented Violet, Viola odorata, is a precocious flowerer, with fragrant blossoms, long runners, and rounder leaves which are shining and almost without hairs in the spring. In the Box Hill district it is usually white-instead of blue-flowered, and it has been shown by S. M. Walters that of this there are two white varieties, one with bearded and the other with beardless lateral petals. Hybrids with the Hairy Violet are common.
In May the slopes where the Violets grow are bright with the flowers of Milkworts. Of these, two are plentiful on the chalk. On the North Downs the Chalk Milkwort, Polygala calcarea, is locally abundant and may be known from allied species by the rosettes of broad leaves at the bases of the flowering stems. These rosettes in turn are produced on wiry stems which lead back to a central root. The arrangement is not always easy to follow when the plants are growing in thick turf, but if you can find one on chalk rubble with very little surrounding vegetation there is no difficulty. The colour of the flowers of the Chalk Milkwort is usually a delightful bright blue, but they are occasionally white and in 1946 I found a whole colony at Buckland, a little farther along the hills, with uniform pale magenta blooms. This species is practically restricted to the chalk and a few places on the limestone, but the Common Milkwort, P. vulgaris, which lacks the leaf rosettes, is very catholic in its soil requirements. It varies a great deal in the colour of its flowers, and sometimes pale and dark blue, and red, may be found growing together.
Salad Burnet, Poterium sanguisorba, is another early-flowering plant which is as common on Box Hill as on most calcareous soils in England and Wales. The young leaves smell and taste like cucumber at one time they were used as an addition to salads. Sheep feed on it eagerly, no doubt finding the unusual flavour an attractive relish to the downland turf. The flowers are collected into roundish heads about half an inch across at the top of a wiry stem a foot or so high.
In May the typical downland orchids start to appear, and for these Box Hill has long been famous. In spite of the depredations of visitors, who pick them selfishly in large numbers because they regard them as quaint and rare, they are still plentiful in the district. I am convinced that if people realised how interesting these plants are they would treat them with greater care and they would be still more plentiful. Perhaps the most fascinating of them all is the Man Orchid, Aceras anthropophorum (Plate VI), which is usually about nine inches tall with many flowers in a dense spike. The lip is usually yellow and shaped like the body of a man with divisions to represent the arms and legs. The sepals are green, edged with brown or red, and curved in the form of a hood. But there is an alternative resemblance to the human race which amuses people with imagination. The hood may be regarded as portraying the head of a dwarf with the lip for his flowing beard. Surrey and Kent are the counties where Man Orchid is to be found in the largest numbers—the farther one gets away from the south-east the less plentiful it is, and it is not found at all in the west of England, Wales, Scotland or Ireland.
The Fragrant Orchid, Gymnadenia conopsea, and the Pyramidal Orchid, Anacamptis pyramidalis, flower a little later. As they are often confused by beginners they are shown side by side on the same colour plate (Plate 5) so that the differences can be clearly seen. In addition to those obvious in the picture it should be noted that the Fragrant has a most delightful scent rather like a carnation (though some people find it over-strong), and the Pyramidal has erect guiding plates at the base of the lip which are found in no other British orchid. Some years ago my friend W. H. Spreadbury found a most remarkable specimen on Box Hill in which all the individual flowers appeared to be upside down. Actually they were the right way up, for in the Pyramidal, and most other British orchids, there is normally a twist in the ovary and this had not been made. This aberration has never appeared in the same spot again.
The Bee Orchid, Ophrys apifera, is one of our best-known wild flowers (Plate 6) and is all too frequently picked. The resemblance to a Bee visiting a flower is so close that children are often afraid to touch it, and it would seem likely that bees themselves are aware of the likeness. Darwin showed that the orchid was commonly self-pollinated, but almost certainly cross-fertilisation also occurs and certain bees may be the agents.
The Musk Orchid, Herminium monorchis, like the Bee, varies greatly in numbers from year to year, but I have never failed to find a few plants in certain places on and near Box Hill. It is a small slender plant, usually about six inches in height, and extremely inconspicuous. A very strong and pleasing smell of honey is given off by the rather tubular yellowish flowers, which are less than a quarter inch long. It has a long flowering season but July is the best month to search for it. Autumn Lady’s-tresses, Spiranthes spiralis (Plate 7a), is about the same height but a rather stouter plant, flowering in August and September—the last of our native orchids to blossom. The small white flowers are very sweet-scented and are arranged in an extremely elegant spiral round the stem, twisting sometimes from right to left and sometimes in the opposite direction. As a result there is a certain resemblance to old-fashioned ways in which ladies once twisted their hair. Unlike most of our orchids, Autumn Lady’s-tresses has no rosette of leaves at the base of the flowering stem, these having withered earlier in the summer. Instead there is a new rosette about an inch away which lives through the winter and decays before the flowers appear the following August. This may be compared with the Bee Orchid, of which I have found leaves under light snow on Box Hill in February soon after they appeared above ground. These are still to be seen at the base of the flowering stems in summer and only wither as the blooms turn to seed. Lady’s-tresses is most abundant on the parts of the hill most frequented by trippers and they often picnic in their hundreds quite unaware that an orchid is growing all round them. There are other orchids still to be found on the grasslands and in the woods of Box Hill.
Having followed one group of plants through the summer, it is now time to return to the June flowers. At this season yellow blossoms predominate, and one of the most common and conspicuous is Common Rock-rose, Helianthemum chamaecistus. This is a low shrubby plant with flowers about an inch across. The delicately thin fugitive petals drop almost immediately they are picked. Generally they are of a uniform buttercup yellow, but rarely there are orange spots at their base, and sometimes they may be sulphur or even white. These variations are constant on the same plants from year to year, and once located they can generally be seen again in other seasons in the same place.
The next three plants are all members of the Leguminosae (Pea Family). Kidney Vetch, Anthyllis vulneraria, owes the second part of its scientific name to its supposed vulnerary (wound-healing) qualities. The flowers are usually pale yellow, and in fruit the calyx becomes white and inflated. Sheep are very fond of it and on the Continent the plant is cultivated on a considerable scale, but it is rarely grown over here. Common Birdsfoot Trefoil, Lotus corniculatus, has bright yellow flowers with the standard striped with red at the base. As they go over, the colour deepens and becomes more or less orange, and when dried for herbarium specimens there is sometimes yet another change to green. The plant gets its popular name from the brown cylindrical pods spread out finger-wise, thus recalling the foot of a bird. These pods twist suddenly as they split on maturity and the movement throws out the seeds a little distance from the parent. Horse-shoe Vetch, Hippocrepis comosa, has more graceful flowers of a paler yellow with delicate brown lines marked on them. There should be no difficulty in distinguishing it from the Birdsfoot Trefoil by the leaves, which have about 7 to 11 elliptical leaflets minutely pointed at their ends, and also by the pods. These are brownish, about an inch long, curved into a semi-circle or ring, and made up of a series of joints, each of which is swollen over a single seed—a second seed in each joint being usually abortive. One might expect the pods to split open across the narrow joints, but in fact the breaks take place through the widest parts. Horse-shoe Vetch is hardly ever found off calcareous soils, on which it is very widespread.
Fairy Flax, Linum catharticum, is a slender wiry little plant with small glaucous green stem-leaves in pairs, and numerous white flowers about a quarter of an inch across with a yellow eye. In some of the books it is called Purging Flax, with allusion to its purgative qualities. A seventeenth-century recipe recommended bruising the plant and then placing it whole in a pipkin of white wine left on the embers of a fire to infuse all night.1 The writer referred to it under the pleasant name of “Mil-mountaine” and warned his readers that the effect was somewhat drastic.
I have always had a soft spot for Squinancywort, Asperula cynanchica. Its pink flowers are an ornament to most of our chalk downs in June, and on the limestone it goes as far north as Westmorland—its northern limit in Europe. But it is the quaintness of the name, which rolls so easily off the tongue, which pleases me. As Pryor puts it, this was earned on account of “its supposed efficacy in curing the disease so-called in old authors, viz. the quinsy.” The French and medieval Latin names are very similar, and there is no doubt that the English name has come right down to us from the days when the study of plants was in the hands of simplers and old wives.
Downland flowers often bloom over such a long period that it is particularly difficult to arrange them in the sequence at which they are at their best. Thus Yellow-wort, Blackstonia perfoliata (Plate IVb) may be in blossom as early as the end of May—yet I have seen it out as late as October on Box Hill. The flowers are the brightest of yellows and make a pleasing contrast to the characteristic undivided glaucous leaves which are arranged in pairs joined round the stern (connate). It is a true calcicole of wide distribution in our islands though less common towards the north. The flowers close up at night. The small genus to which it belongs was named by Hudson in honour of John Blackstone, an English botanist and apothecary who died in 1753.
Hoary Plantain, Plantago media, is abundant on chalk hills and easily recognised at all times of the year by the oval, hoary leaves. The flower-stems are even more woolly, and when the heads show the purple stalks of the yellowish-white anthers they are quite attractive. Like its relatives which can withstand so much trampling in garden lawns, the Hoary Plantain is a most difficult plant to destroy and hence it is to be found even on the most frequented parts of the downs. Much the same can be said for the Stemless Thistle, Cirsium acaulon (Plate 2), which is able to put up with any amount of bad treatment. The name would often seem to be a misnomer, for not infrequently the stems are of sufficient length to be noticeable, but nevertheless more ramblers can claim acquaintance with its spiny leaves than with its flowers. As it increases very rapidly vegetatively, it forms large patches—often a yard or two yards across—from which other vegetation is more or less excluded. To select one of these inadvertently as a resting-place is an uncomfortable experience for which the handsome purplish-red heads of flowers nestling amongst the leaves are small compensation.
Two Umbellifers are very common on chalk. Some of the quieter parts of Box Hill have masses of Wild Parsnip, Pastinaca sativa, a coarse plant with bright yellow flowers. Various subspecies are recognised on the Continent but, although the leaf-shape of our downland material varies a good deal, no attempt has been made to “split” the Parsnip in Britain. Wild Carrot, Daucus carota, should also be recognised very easily by any gardener who has ever allowed his crop to go to seed, though in this case also the cultivated and wild plants are not identical. Recent research has shown that the Carrot of the vegetable garden is probably derived from a Mediterranean subspecies and not from our wild British plant. The heads of flowers arranged on stalks set out like the ribs of an umbrella are worth careful examination. Those on the outside are irregular with the petal directed outwards enlarged to make the head more prominent. The inner flowers have all the petals more or less the same size, and careful examination with a lens will show that some are male and others female. The central flower is often a deep purple colour.
By August most of the chalk down flowers are those which will go on until well into the autumn. Whereas the predominant colour earlier is yellow, blues, reds and purples now become general. Two Scabiouses are particularly characteristic. One, the Small Scabious, Scabiosa columbaria, is widespread on chalk and limestone in Britain. Each flower-head consists of some 70 to 80 separate bluish-lilac flowers collected together in the same way as the daisies (Compositae). Those round the edge are rayed, making the whole head more conspicuous, and in these the anthers are pushed out and expanded well before the stigmas mature. The fruits are hard and spiny, with another covering (the involucel) outside the calyx. They are crowned with five dark purple spines with teeth all along their edges, and these catch in the hair of animals or the clothing of humans and thus assist in the dispersal of the seeds.
The Small Scabious has the parts of its flowers in 5’s, but in Field Scabious, Knautia arvensis, they are in 4’s. This has much larger and more purplish blooms, and although common on chalk and limestone it also occurs on other soils. Usually in all the flowers of the heads the anthers open first, shed their pollen, and wither before the stigmas are protruded. In this way self-pollination is rendered very unlikely. But Darwin also showed that some plants occur with only female flowers and these are said to be more numerous early in the season. It seems that their numbers as compared with the hermaphrodite blossoms vary in different parts of the country.
Thistles are usually regarded as pests rather than flowers of beauty, but although downland farmers have good reason to destroy it, the Musk Thistle, Carduus nutans, is a handsome plant, as the illustration (Plate 3) shows. The blooms smell of musk and are protected by a series of rather broad bracts; there is only one head at the end of each downy stalk, which is leafless towards the top. Carline Thistle, Carlina vulgaris, also shows a strongly marked preference for calcareous soils. Its pale-yellow “everlasting” flowers expand fully in sunshine in dry weather and close up again when it is wet. On this account country people sometimes collect them for use as barometers, or rather as hygrometers—for it is the humidity of the atmosphere and not the air-pressure which they indicate. On the downs they last well into the winter until the wind and rain destroy them.
Dark Mullein, Verbascum nigrum (Plate IVa), is another very characteristic plant of calcareous soils in the south, although it is absent from the northern limestones. It is easily distinguished from the other Mulleins by the numerous and usually unbranched stems, which come up from the rosette of leaves with heart-shaped bases, and by the beautiful tufts of purplish hairs on the stamens. It is said to be absolutely sterile to its own pollen, so cross-fertilisation is essential to the production of seed. The books usually give the Dark Mullein as a biennial but this is certainly not always true. I have known Surrey plants which have lived for years, increasing annually in size so that eventually they became more like a small colony than a single individual.
Great Mullein, V. thapsus, sometimes called High Taper, has long dense spikes of stalkless, rather pale yellow flowers and woolly leaves with bases which run down the stem (decurrent). Almost the whole plant is covered with matted white hairs which, when examined under the microscope, are seen to be intricately branched. This wool, stripped from the leaves, was formerly used as tinder owing to the ease with which it ignited when dry. The Great Mullein, like most of its allies, is a biennial, and in the first year it produces only the rosettes of woolly leaves which are such familiar sights in spring and autumn. On Box Hill I have found hybrids with the Dark Mullein showing a perfect mixture of the characters of the two parents.
I always associate August on the chalk downs with the delightful scents of leaves of Labiates—Wild Thyme, Thymus drucei, Marjoram, Origanum vulgare, Wild Basil, Clinopodium vulgare, and other less common plants. The first two are closely related to foreign species grown in herb gardens for use as flavourings, but the native Thyme and Marjoram will serve as coarser substitutes. In addition to the “complete” blossoms, which contain fully-formed stamens and pistils, there are female flowers in which the stamens are aborted. These appear a little earlier and are smaller, so that a careful search is necessary to find them.
The Eyebrights, Euphrasia spp., are extremely interesting from several points of view. They are partially parasitic in that they normally obtain part of their food materials from other plants by means of attachments from their roots on to those of their hosts. For this purpose they attack Grasses, Sedges and probably other plants, and the dense mass of roots present in the downland turf provides them with excellent opportunities.
Recent researches have shown that the British Eyebrights, all formerly included under the aggregate name of Euphrasia officinalis, can be divided into about 25 species. Some of these are very distinct and very little study will suffice to distinguish them. The most handsome of the kinds found on calcareous soils is Large-flowered Chalk Eyebright, E. pseudokerneri (Plate 20), for which the type locality is Box Hill. Pugsley described this as “a beautiful plant of dwarf, robust and bushy habit, with small, dark foliage and large, bright flowers.” It is one of the autumn gems of the downs, coming into flower in August and being at its best in September. Well grown plants are a mass of bloom, and the individual blossoms seem enormous in comparison with the size of the plants. It is fairly common on the South and North Downs, and also found in East Anglia, but it is one of the few British species which, so far as our present knowledge goes, are endemic—i.e., not found outside this country.
The other species which is common on Box Hill is the Common Eyebright, E. nemorosa. This has much smaller flowers which are less prettily marked and it is more straggling. For those who are interested in such fine points, it should be mentioned that, as found here, it is usually the variety calcarea, which is dwarfer and coarser than the usual state of the species.
Clustered Bellflower, Campanula glomerata, is common on calcareous soils in all parts of England and extends into Wales and Scotland. It is not surprising that over such a wide range it varies very greatly in size. The Box Hill specimens (Plate 4) may be taken as about the average, and many people think they have found something different when, on the wet limestone cliffs of the north, they find strong, robust plants some two feet high with much more numerous flowers and less hairy leaves. The other extreme is seen on very dry coastal cliffs in Sussex and the Isle of Wight, where it may be found a mere inch or two tall, with only one or two flowers, and extremely hairy. It was such plants that led the painstaking Dr. William Withering into a first-class botanical howler a little over a century ago. On two diminutive specimens of the Clustered Bellflower he described a species new to science, and went so far astray that he classified them as Gentians—under the name Gentiana collina!
The only true Gentian to be found on Box Hill is far less beautiful than the rarer species described in later chapters. Autumn Gentian, Gentianella amarella, has reddish-purple flowers which open and close with surprising speed, according to changes in the temperature. Since it is warmer when the sun is shining, the opening is generally observed as clouds roll away, and the time taken for the change may sometimes be as little as 20 seconds. The bitter taste of the stem and leaves is said to offer protection against grazing, but this is certainly of little value in the face of attacks from the hungry rabbits of the downs When they nibble the young shoots down to ground level the plants branch out from the base and grow into very floriferous bushy little tufts on which the flowers are sometimes divided into 4’s instead of 5’s. It was from Box Hill that Pugsley described a new variety of the Autumn Gentian with greenish-white tetramerous (divided into 4’s) flowers as variety pallida.
Finally there are two plants which belong to bushy places and wood borders rather than to the chalk grassland. Ploughman’s Spikenard, Inula conyza, has small yellowish flowers collected into numerous heads about half an inch long and is usually about a couple of feet in height. The leaves are rather like those of the Foxglove, and more than once I have thought that I had found this calcifuge on chalk until I quickly realised my mistake. In a similar difficulty, rub a leaf, and if it has an aromatic smell it is certainly not Foxglove. It was the “sweet and aromaticall flavour which his roots containeth and yieldeth” which led the Elizabethan Gerard to confuse this plant with a foreign herb with roots which provided an ointment, and hence to the application of the name “Plowmans-Spikenard.”
Deadly Nightshade, Atropa belladonna (Plate 10), is common on Box Hill—perhaps too common in view of the large number of children brought there for picnics. All parts of the plant are poisonous as they contain the deadly alkaloids atropine and hyoscyamine in various proportions, but drugs are generally prepared from the leaves and roots. It is the fruits, which are about the size of cherries and of very attractive appearance, which are responsible for most cases of accidental poisoning. Somewhat strangely it seems that many animals are immune from serious effects following their feeding on Belladonna. Birds eat the berries. Rabbits gnaw the leaves and stems and, as shown in the illustration, the foliage is often eaten by caterpillars. On limestones Deadly Nightshade is sometimes locally abundant, but elsewhere it is generally found only round abbeys and similar places where it was probably originally planted for medical use.
The plants discussed in this chapter are all to be found on Box Hill and many of them are widespread on calcareous soils. Readers from all parts of the country will be able to find some of them in their own districts; others are restricted to the south of England. They do not exhaust the treasures of the hill; on the contrary it must be stressed that the visitor will find many other fascinating plants for himself. The selection of characteristic chalk plants which has been given will serve, by comparison with other districts, to illustrate the common factor which runs through all the floras of calcareous soils in the British Isles. Distance brings into effect the influence of the limits of geographical distribution of species. For this reason it will be found, as a general rule, that the farther we get away from Box Hill in the following chapters, the greater the differences in the kinds of wild flowers observed.