Flowering Plants of Woodland Shade
Plants that grow under woodland trees must be able to tolerate a certain lack of light, although not many flowering species grow in the deepest shade. In early spring, before the new foliage cuts out too much light, those species that prefer damp, shady conditions appear in profusion.
Shade-loving plants find that woodland provides the damp, sheltered conditions they need for growth. In deciduous woodland, the characteristic ground flora consists of plants that flower in early spring while the trees are still bare and the sunlight reaches down to the woodland floor. The most familiar plants in this type of woodland are primroses, violets and wood anemones, which often flower before the leaves open on the trees above I hem.
The density of shade depends upon the type of woodland; beech trees have leaves that are thick in texture and arranged in a close pattern that allows little light through, while in other mixed broadleaved woodland the shade may be more diffuse. In conifer woods and plantations the shade can be very dense. Especially when the trees are mature. Here only ferns, mosses and a few helleborines and orchids can tolerate the lack of light.
Woodruff is a wood-land species that grows on damp, calcareous soils throughout Britain. In some areas it grows in profusion and is welcomed for its fresh growth in early spring. The small flowers, measuring only 5mm in diameter, have dense white petals and form umbellate heads. These are set off by the fresh green leaves which are arranged up the stem of the plant in symmetrical, rather rigid, whorls of six.
Sometimes known as sweet woodruff, this little plant, which is hay-scented when dried, contains the aromatic substance coumarin. In the past, it was gathered and used for strewing on floors in the home, for laying between clean linen and was also added to the stuffing in mattresses. The dried plant was also powdered and dissolved in wine to make a tonic drink known as ‘Waldmeister Tea’: and in dried form it is still used today as a pleasant herbal tea.
White woodland carpet
Although wood-sorrel-another white-flowered species-grows on shady rocks on mountains in the north and in sheltered hedgerows further south, it is mainly a woodland species. Less than 15cm (6in) high, this early flowering species may carpet the ground in beech woods. It is also found in oakwoods and mixed woodland, often in the leaf mould at the base of trees or in clefts of tree trunks above the ground. Here pockets ofmay first be colonised by lichens and mosses in which seedlings of small flowering plants can eventually germinate and grow.
The first flowers have distinctive white petals delicately traced with lilac-coloured veins, but they set few seeds, however. Later in the summer there is a second flowering when the flowers are smaller, short-stalked and without petals. These inconspicuous flowers are self-pollinated and set seed in quantity, although wood-sorrel also spreads by means of its creeping underground rhizomes.
The spring flowers nod forward at night or in the rain to keep the pollen dry. And the three leaflets fold back at night. They also stay folded in strong sunlight so that the delicate leaf surfaces do not receive the direct rays of the sun.
Country children often nibble the leaves of the plant; these contain tiny amounts of oxalic acid, which give them a pleasant, sharp taste. In small quantities this does no harm. In fact, in centuries gone by, when winter diets seemed very dull by the end of the season, wood-sorrel leaves were welcomed for their sharpness in spring salads. They were also used to make a green-coloured sauce for which the plant was valued and sometimes cultivated.
Herb bennet or wood avens, which grows in shady areas, is found through-out Britain as a wayside flower in hedgebanks as well as in woods. The flowers are rather small and few and the soft yellow petals are sometimes partly covered by the green sepals. As the flowers wither, the seeds ripen in a round brown cluster of hairy fruits. Each fruit has a long hooked bristle which catches in fur, feathers or clothing and ensures the dispersal of the seed.
Herb bennet has been known since the Middle Ages, when it was thought to be a blessed herb, its name being taken from the Latin herba benedicta. It was once gathered by country people to boil in broth or ‘potage’ and was grown in gardens for this purpose. The roots have a fragrant, clover-like scent; like the woodruff herb, this ‘clove-root’ was used to scent linen closets.
The colourful wood crane’s-bill also grows in a number of different habitats: on mountains, in meadows and on rock ledges, as well as in hedgerows and woodland. Its Latin name Geranium sylvaticum, however, means ‘geranium of the woods’ and was given to the species by Carl Linnaeus in his classification system of 1730. In Linnaeus’ native Sweden, wood crane’s-bill is a common plant of deciduous woodland. While further south in its range it grows away from woods. In the Alps, the deep blue-violet of the paired flowers may often be the dominant colour of the hay pastures.
In the British Isles, the wood crane’s-bill has an unusual distribution pattern, generally widespread and common in Scotland and northern England, but with less than five localities in Wales and Ireland. It has been introduced in a few places in southern England, but does not occur there as a native wild flower.
Green hound’s tongue is now very scarce in Britain. A plant of woods and hedgerows, it was once widespread throughout central and southern England, but is known now in less than ten localities. The causes for this decline are not fully understood. The species is near the limit of its range here and possibly variations in climate through the years, or changes in woodland management, could have altered the conditions necessary for its growth. In recent years, trees were felled in woodland where only two or three specimens of green hound’s tongue were known and in the following year several hundred of these plants came up in the cleared area. This great abundance of plants shows that the seeds were lying dormant in the soil, waiting for favourable conditions before germinating.
Another, more familiar, species of hound’s tongue grows in Britain. This is the common hound’s tongue, which has grey leaves felted with hairs. It is found on chalk grassland and dry sandy soils, often near the sea-very different conditions to the damp shade required by the green hound’s tongue of the woodland.
Herb Paris is another woodland plant that is rare in the British Isles. It has an unusual structure, with the four leaves near the top of the stem arranged in a single whorl, just below the single green star-shaped flower. This flower has four sepals and four narrow petals, with eight thin, pointed yellow stamens. The flower is followed by a single, poisonous black berry, often ringed by the still persistent stamens, petals and sepals.
Found in damp woods on calcareous soils, Herb Paris grows in the south on chalky soil under beech trees, often with Solomon’s seal and dog’s mercury. In northern woodland on limestone soils it can be found under ash or wych elm trees and it also grows in the crevices of bare limestone pavement. These deep, narrow clefts or grikes produce similar conditions to those of woodland-shade. Moisture and shelter; the grikes are therefore colonised by several species of woodland plants.
Woody nightshade or bittersweet is a plant of many different habitats, including shingle beaches and waste ground as well as woods and hedges. Although it grows well in damp, shady woodland con-ditions, it is not dependent on them and is also found at the edges of woods. It is a straggling climber, with stems too weak to support the rather heavy heads of flowers and berries. So for support it grows between the stems of shrubs, or in hedges. The flowers are an unusual shape, with a ring of blue petals which fold back as the flower ages, and the yellow stamens are fused together in a forward-pointing cone. The berries are very glossy and green when they first appear, eventually turning yellow and finally red. In early autumn it is occasionally possible to find a spray of berries with all three colours appearing on a plant together in one cluster.
The name bittersweet is derived from the taste of the berries. Due to the presence of a toxic chemical in the plants, they taste bitter at first, and then sweet: and will make you sick if eaten. The plant is sometimes confused with the very poisonous deadly nightshade. Which has cherry-sized shining berries, borne singly. When ripe, these are black rather than red and should never be eaten or touched under any circumstances.