Fraxinus is a genus (biological classification) of flowering plants in the olive and lilac family. Native mainly in mainland Europe, the ash has long opposing leaves with serrated edges. The ash is often the last to come into leaf in spring and the first to fall in the autumn. The European Ash, Fraxinus excelsior, is commonly affected by the fungus Hymenoscyphus fraxineus, causing ash dieback - this is what caused the demise of one of the two ash trees in the play area adjacent to the double lakes in GWP south.
A genus of deciduous trees native to temperate Europe, Asia and North America. Beeches are high-branching with tall, stout trunks and smooth silver-grey bark. The European beech Fagus sylvatica can develop into giants which tower over other woodland trees, and can live to 300 years. As owners of beech trees know, their leaves are resistant to decomposition and good at clogging gutters.
Fagus sylvatica f. purpurea
The copper beech is related to the European beech with many similar characteristics including the smooth bark, except that the leaves of this more ornamental variety are red to purple in colour. The colour is thought to be a mutation first noticed in the Possenwald forest near the town of Sondershausen in Thuringia, Germany. Experts assume that about 99% of all copper beeches in the world are descendants of this copper beech.
EUROPEAN CRAB APPLE
The Latin name means "forest apple". The crab apple often appears more like a bush than a tree, and can live 80-100 years. The fruits, while not suitable for eating raw, can be made into crab apple jelly. The crab apple is often used as rootstock for domestic apple trees, which are a separate evolutionary strain (Malus domestica), selectively bred for the qualities we value such as sweetness and longevity.
This is a deciduous tree with a fissured cork-like bark with smooth-edged leaves in opposite pairs. By contrast, the sycamore tree (Acer pseudoplatanus) has five tooth-edged lobes. Flowering in spring, the field maple later bears fruits with wings 180 degrees apart. In North America the tree is known as hedge maple and in Australia, it is sometimes called common maple. In Nottinghamshire it was known locally as dog oak. The field maple gives a colourful display in autumn.
Horse chestnuts are native to the temperate northern hemisphere, extending to North America. This tree can be recognised in spring by its large five-petal leaves which emerge from stout shoots with resinous sticky buds. The seeds - conkers - are toxic, but attract children to collect in autumn. A good supply can be found from the mature row of horse chestnuts in Smallbone Rec in Britwell Road north of Didcot Civic Hall.
There are about 30 species of lime tree, native throughout the northern hemisphere. The European species of the tree is known as linden, and basswood for the North American species. Limes are long-lived - occasionally 1,000 years. The leaves are almost circular, but with a pointed tip. Limes produce pea-like fruit. Aphids are attracted by a rich supply of sap, and these are often eaten by ants. The resulting dripping of excess sap is why it's not a good idea to park under a lime tree.
Populus nigra Italica
The Lombardy poplar is easily recognised by its height, its slender spread, and having its branches parallel to the stem. The trees are often grown in a line to make a windbreak, but live only about 50 years. In 1884 in France, the true Lombardy poplar was crossed with P. nigra betulifolia to produce a tree which is better adapted to the cool, humid climate of northwest Europe, and is most often grown in the UK.
This evergreen tree with a long straight trunk has thick, tough triangular leaves with sharp edges. Originally from the lower slopes of the Chilean and Argentine south-central Andes, typically above 1,000 m, young trees have a broadly pyramidal habit, while older trees show an umbrella shape after lower branches have fallen. The monkey puzzle prefers a temperate climate with abundant rainfall, and is very frost-hardy. There are several examples in upper Broadway near Didcot Civic Hall, and in Lydalls Road.
Ivy (Hedera Helix)
The common, pedunculate, European or English oak is a tree related to the beech family. Oaks are generally regarded as supporting more species of wildlife than any other native tree in the UK. Estimated to number 2,300, these organisms range from bacteria to fungi, lichens (fungi in symbiosis with algae), free algae, mosses, vascular plants, invertebrate animals, birds and mammals. As a tree with a large canopy, the oak is an important mitigator of climate change by absorbing carbon dioxide.
Mature oaks shed varying numbers of acorns annually. Scientists suggest that shedding excess numbers allows the oaks to satiate nut gathering species which improves the chances of germination. Every four to ten years, certain oak populations will synchronize to produce almost no acorns at all, only to rain them down excessively the following year, known as a "mast" year. The year preceding the mast year is thought to starve off the mammal populations feeding on the supply, thereby increasing the effectiveness of the overproduction in the mast year that follows.
Oaks can live to 1,000 years, but are mature at 75, and live on average 150-250 years. Despite this longevity, the oak has its fair share of natural enemies. Sometimes in summer, an apparently healthy oak will drop a large branch, which some sources say is more likely following heavy rainfall after the absence of rain for more than three to four weeks. Oaks are also susceptible to sudden oak death - a water mould that can kill within just a few weeks.
Oak wilt (a fungus related to Dutch elm disease) is also a threat, as well as wood-boring beetles and root rot in older trees that may not be evident until a tree falls in a strong gale. Other fungi that threaten oaks include Ganoderma and oak bracket fungus. Since 2009, a new and yet little understood disease of mature oaks - acute oak decline - has been reported in parts of the UK. All these threats make it important that we protect oak trees and minimise threats from human activity.
Ivy growing on a tree doesn't harm it at all, and supports at least 50 species of wildlife. (Source: Woodland Trust)
Also known as the evergreen or holly oak, the holm oak is native to the Mediterranean region. Originally susceptible to severe frost, the holm oak has successfully extended its original range. The first trees to be grown from acorns in England are still to be found within the stately grounds of Mamhead Park, Devon. The tree develops a huge head of dense leafy branches, as can be seen above the gates of the private grounds of The Rectory on Foxhall Road. Newly planted holm oaks surround parts of Boundary Park in Great Western Park (north of Didcot Road).
The pin oak or swamp Spanish oak is a medium sized deciduous tree, fast-growing and pollution-resistant, so often grown as a street tree. The upper branches point upwards, the middle branches are at right angles to the trunk, and the lower branches droop downwards. In autumn the tree usually has brightly coloured leaves. Leaves have either 5 or 7 lobes with deep cuts between. The most notable planting of pin oak is in the north part of GWP – a row of 25 along The Avenue. There is also a large pin oak outside Boots in the Orchard Centre.
A distinguishing feature of the plane tree is its spiky globular fruit which can hang throughout winter. There are a dozen species of plane, but the commonest in the UK is a hybrid version – the London plane - which is resistant to pollution and therefore used as a roadside tree. Fossil records of plane fruits have been dated to 115 million years. Two known plane trees in Didcot grow on and near the Wantage Road roundabout.
Sometimes known as false acacia, or black locust in its native eastern United States, this tree is a relative of the pea and bean. Distantly related to the subtropical acacia, Robinia branches have sharp spines and compound leaves with thirteen leaflets. It prefers a shade-free location. There are white flowers and pea-like seed pods. A mature example grows on the semicircular grassy area of Abingdon Terrace (Wantage Road).
The evergreen Scots Pine ranges from western Europe to Siberia, and as far north as the Arctic Circle. The tree has a long straight trunk, topped by a rounded or flat-topped mass of foliage. Its bark varies from grey-brown to orange, and its cones open 22-24 months after pollination. There are four examples seen in Manor Road, and along Broadway where Drake Avenue joins Wantage Road. The related tree in the grounds of Didcot Methodist Church on Broadway is a Corsican Pine (Pinus nigra) with black bark (see "Unusual and Rare Trees" below).
The two members of this family that originate in California are the Giant Sequoia - sometimes called Wellingtonia in the UK - and the Coast Redwood (Sequoia sempervirens). There are several specimens of giant sequoia in Didcot, to judge from their stem shape, cone size and soft bark. Separately there is also a smaller Dawn Redwood (Metasequoia glyptostroboides), originating from south-central China (see "Unusual and Rare Trees" below). All have a distinctive red bark. The only accessible specimen is at the Northbourne Centre. In 2021 this tree was 25m (80 feet) high – certainly one of Didcot's tallest trees.
This tree is characterised by white peeling bark, and slender pendulous twigs. The catkins are flowers, and the tiny winged seeds are widely scattered by the wind. Many species of birds and animals are found in birch woodland, the tree supports a wide range of insects and the light shade it casts allows shrubby and other plants to grow beneath its canopy. The versatile silver birch grows from western Europe east to Kazakhstan and from northern Morocco to Siberia and Mongolia. In Didcot there are examples around the War Memorial in Smallbone Rec, and in Abingdon Terrace (Wantage Road).
This tree is only distantly related to the horse chestnut, despite bearing similar "conkers" and has a similar red, rather than white flower. The seeds are often eaten roasted on an open fire. Sweet chestnut trees are one of Earth's longer-lived species, living to an age of 500 to 600 years, 1,000 in cultivation, and there is a 2,000 year old tree in Sicily. Its native habitat is the Mediterranean, although it has now spread to most of Europe after surviving the Ice Age in warmer southern locations.
The willow grows quickly, but has a relatively short lifespan of between 40 and 75 years. Its drooping habit is characteristic, with branches often reaching the ground. The willow soaks up water from the ground after rain, but it doesn't require a moist location, so it can tolerate drought, which makes it a faily hardy tree. Despite the last part of its botanical name, the weeping willow originated in China, where it sheltered and provided wood for oases around the Gobi desert. It was introduced into England in 1730 from Aleppo in northern Syria. There is a large example at Avon Way in Ladygrove Park.
The yew is an evergreen tree in the conifer family, native to all but the north of Europe, and parts of Africa, Iran and Asia. Most parts of the plant are poisonous. All Saints' churchyard in Lydalls Road contains an ancient example – Didcot's oldest tree and one of the oldest in the country. This tree is further described in this website's Top 20 page.
UNUSUAL AND RARE TREES
The above list included the giant sequoia, of which there are believed to be four examples in Didcot, and its relative the coast redwood, which is not thought to grow in Didcot. The third relative, originating from China, is the endangered dawn redwood, with a generally straight trunk that tapers quickly as it grows taller, a fluted bark, small cones, but unlike its cousins it is deciduous. There is one known example in Didcot, in Orchard Close, off Haydon Road. This tree is in a front garden, so if you visit this tree, please do so from a distance and respect the resident's privacy. The dawn redwood is an endangered species.
A VERY RARE GROUPING
See botanical names in text
Also in Orchard Close there is a group of other rarer trees all growing together: a blue cedar (Cedrus Atlantica Glauca) which has needle-like leaves, a Deobar cedar (Cedrus deodara) also known as the Himalayan cedar and native to that region between 1,500 and 3,200m elevation. It has drooping foliage with needle-like leaves, and is the national tree of Pakistan, and a smooth Arizona cypress (Cupressus arizonica var. glabra) which is native to the American southwest, particularly around Sedona, Arizona.
The Corsican pine is also known as the Austrian pine or black pine, because of the colour of its bark, which is much darker than a Scots pine. Its natural range is across southern Mediterranean Europe from the Iberian Pensinsula to Corsica, Sicily, Turkey, and Cyprus, as well as Crimea and the high mountains of Northwest Africa. It is found at elevations ranging from sea level to 2,000 metres (6,600 feet). The black pine has naturalized in parts of the midwestern states of the USA, south of the ranges of native pines.
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