Walks index

Avenues of Trees


Cambridge is a beautiful city. If you asked people why, they would talk about the ancient college buildings of the university, or the narrow medieval streets, or perhaps the green spaces. That is all true, but I also like the trees, especially the tree-lined avenues, so this page is dedicated to them. I describe four important species of tree in Cambridge, tell you how to identify them, and where to find them. This is definitely not a well-defined walk. Some of the trees feature in the other walks. Or if you are walking through Cambridge, you could keep a lookout, or even make a short diversion, to see some of these trees. There is a scale at the top of the map. 200 metres is similar to 200 yards and a kilometre is about half a mile. The avenues are marked in dark green and the name of the tree in red. Click on the red (not the green), or on the links, for a description and some photos.

Trees Identification of trees
Horse chestnut
London plane
Lime or linden
Willow
Bark
Tree shape
Leaves
Flowers/Seeds
Willow Willow Willow Horse chestnut London plane London plane Lime or linden Lime or linden Lime or linden

Map of some tree-lined avenues

Click on the photos for a bigger version.


Horse chestnut

There are many fine horse chestnut trees in Cambridge. There is even one in the middle of the police station (you can see it from Warkworth Terrace, off Parkside). But they are mostly single trees. There is one avenue of horse chestnuts, Victoria Avenue, between Jesus Green and Midsummer Common. These views show the two ends of the avenue. See the second river walk from Elizabeth Way to Magdalene Bridge.

Avenue of horse chestnut trees - Victoria Avenue Avenue of horse chestnut trees - Victoria Avenue

The horse chestnut is well-known. It is not a native tree, being introduced to Britain in the late sixteenth century. In spring the tree is covered with flowers, either cream or red (these are different species). The tree can grow very big, both tall and wide.

Horse chestnut tree

Horse chestnut leaf

The leaf is distinctive. They are compound, with 5 to 7 leaflets. You can just see the conker cases start to form. In autumn children collect the conkers which are beautifully shiny when they first leave their covering.

To play the game of conkers, make a hole in the conker and thread some string through, stopped with a knot. One child holds up the string with the conker dangling. Another child tries to hit it with their own conker. When successful, one (or other) of the conkers are smashed. The surviving conker then becomes a 'oner' (because it's broken one conker). There is even a World Conker Championship! By the way, conkers are slightly poisonous. They should not be confused with chestnuts, which come from a different tree.

Unfortunately, British horse chestnut trees are threatened by the Cameraria moth. The caterpillars of this moth burrow into the leaves, leaving brown spots. Eventually the whole leaf turns brown. This happens during the year, so the trees look fine in early summer, when I took these photos. By late summer, it is hard to find a green horse chestnut tree in Cambridge. The photo of the tree on the right, below, was taken in mid-September, and other trees are still green.

Damage to horse chestnut leaf by Cameraria moth Damage to horse chestnut leaf by Cameraria moth Damage to horse chestnut tree by Cameraria moth

London plane

Possibly the best avenue in Cambridge is the path in Jesus Green from Jesus Lock to Midsummer Common, lined with London plane trees. The trees interlock their branches overhead, making a cool corridor in hot weather. See the second river walk from Elizabeth Way to Magdalene Bridge.

Avenue of London plane trees in Jesus Green Avenue of London plane trees in Jesus Green

There are plenty more London plane trees in Cambridge. There is a lovely line of big trees along one side of St Matthews Piece, a small green area near the Elizabeth Way roundabout. There are plenty of single trees as well. The Elizabeth Way roundabout has four in the underpass area!

The London plane, despite its name, is not a native British tree, and in fact is modern. It was first recorded as occurring in Spain in the 17th century. It is usually thought to be a hybrid of the Oriental plane with the American plane. It is called the London plane in Britain because there are many of the trees in London. It is widely planted in towns and cities because it seems to thrive in highly pressured urban environments which other trees cannot cope with.

London plane is good in polluted air, partly because the bark sheds, which gets rid of any pollution settling on it. This makes an attractive pattern on the trunk.

London plane bark

London plane leaf

Usually leaf shape is good for identifying trees, but the London plane leaf does look a bit like the leaves of other trees such as sycamore. The bark is a better identifier.

If left alone with space to grow, the London plane grows quite wide. Since it can become a big tree, this means that it ends up taking a lot of space, not a very good thing in a crowded city! The width of the tree can be limited by growing it in an avenue, or with other trees.

London plane tree

Pollarded London plane tree

Another solution is to pollard the tree. The trees above are in Maids Causeway, near Midsummer Common and they have been pollarded. They are pruned heavily at the top of the trunk, so every year grows new growth. This gives them short thin branches and a round appearance, rather like a lollipop.

London plane seed

The London plane seed is rather an attractive spikey ball.


Lime or Linden

Christs Pieces is a town park in the middle of Cambridge, next to the bus station. There are several paths through Christs Pieces, some lined with lime trees. Click herefor more about Christs Pieces.

Avenue of lime or linden trees in Christs Pieces

Avenue of lime or linden trees in Queens Road

Queens Road, to the west of Cambridge city centre, has many trees, including many limes. The road should be Queen's Road, by the way, as opposed to Queens' College. It depends how many Queens were involved. I've found it easier just to leave the apostrophe out!

There are also limes along the edge of Parkers Piece, a green area which hosts many events and is used for sport, especially by a local school who does not have their own sports field. Limes are common throughout Cambridge, both as single trees and grouped together.

Lime trees are native British trees. The name of the tree is nothing to do with the citrus fruit line. It is an altered form of Middle English lind, hence the other name for the tree, linden. Linden was originally the adjective, "made from lime-wood".

The tree shape of mature trees in Cambridge seems to be tall and thin, which makes an excellent tree for avenues.

Lime or linden tree

Lime or linden leaf

The lime leaf looks 'leaf-shaped', but it is distinctive. It is a heart shape with a definite point to the end. It is also slightly asymmetrical, with the leaf bulging out on one side of the stalk slightly more than the other.

Here are the lime flowers.

Lime or linden flower

Limewood is soft, easily worked, and has very little grain, so it is very good for carving. Grinling Gibbons (1648-1721) was a famous master wood carver, and he used this wood. There are examples of his carving in the Wren Library, in Trinity College. You have to pay to visit Trinity College, and the Wren Library has restricted opening times. Click here for details.


Willow

Unlike the other trees on this page, you don't see avenues of willows. Willows grow mostly along side the River Cam, and they are often mixed in with other trees. See the first river walk from Elizabeth Way to Stourbridge Common.

Willows and other trees along the river Willows and other trees along the river

Most people know the weeping willow. There are weeping willows in Cambridge.

Weeping Willow tree

But the tree most associated with Cambridge is the white willow.

White Willow tree

White Willow leaf

Both weeping willows and white willows have long thin leaves, but the white willow leaves are very pale (see left).

The Bumps are rowing races along the River Cam, by both college and Town boats. There is a description of the Bumps here. During the Bumps, successful crews pull in to the bank, and break off willow branches from nearby trees. Then they descorate themselves and their boats, so everyone knows of their success.

Willows are always associated with rivers in England, as in the book The Wind in the Willows by Kenneth Grahame.

The Greek physician Hippocrates wrote in the 5th century BC about a bitter powder extracted from willow bark that could ease aches and pains and reduce fevers. The relevant chemical is now synthesised and sold as asprin.

Cricket bats are made from cricket-bat willow, a hydrid of white willow.


Identification of trees

There are several ways to identify a tree. You can look at a leaf, the bark, the flower, the fruit or nut, or the shape of the tree. Unfortunately there are problems with using any one of these.

Bark

Here are some different tree barks:

Horse chestnut bark
Horse chestnut
Lime or linden bark
Lime
Willow bark
Willow

As you can see, they look very similar. The slight variation in the colour may be because of algae or lichen growing on the trunk.

What is worse, the bark changes with age. Below is the bark of a young horse chestnut.

Young horse chestnut bark

London plane bark

However, some trees do have very distinctive bark. This blotchy bark is enough to identify a London plane.

So there is some point in looking at the bark. The mature trees above have ridges, and are greyish in colour (the green is the algae). Other trees have a smoother bark, such as beech. Other trees have a very distinctive bark such as the London plane. I should think that most people could identify a silver birch as well! So sometimes you can identify a tree by the bark, sometimes it helps to narrow down the identification, and sometimes it is no help at all.

Tree shape

Trees have distinctive shapes, and when you know a tree species well, you may be able to glance at a distant tree and indentify it.

Horse chestnut tree
Horse chestnut
London plane tree
London plane
Lime or linden tree
Lime
White Willow tree
Willow

However, the tree shape may be different for some reason. Young trees may be different. Trees may be grown close together, which alters their shape. They may be damaged by traffic hitting the twigs hanging over a road, or grazing animals might niggle them. Here are two distinctly non-standard shaped trees!

Willow tree

This willow is an old tree but the branches and leaves are new growth. When this is done intentionally, it is called coppicing. Here it looks like an accident, as the tree must have nearly died, but just the trunk survived.

This London plane is pollarded, a pruning technique which reduces the size of the tree. It also changes its shape.

Pollarded London plane tree

Sometimes tree shape is the simplest way to tell similar species apart. Which of these is the white willow, and which the weeping willow?

Weeping Willow tree White Willow tree

Leaves

The most obvious identification method is to look at the leaves. Leaves do vary in colour between different species. However, they can vary during the year in a single tree. Leaves can change colour in autumn, of course, but they can be bright green in the spring and darken during the summer. The leaf shape is easier.

Horse chestnut leaves are well-known, of course. The lime leaves are also very distinctive once you have noticed the point at the end, and the asymmetry of the leaf.

Horse chestnut leaf
Horse chestnut
Lime or linden leaf
Lime

However, other trees are a little trickier.

White willow leaf The white willow leaf (left) is much the same shape as the weeping willow (right), although the colour is different. But the tree shape would be a better way to distinguish between them.

Weeping willow leaf

The London Plane leaf (left, below) looks similar to other leaves such as the sycamore. I'm not sure what the leaf on the right is. It may be a sycamore! When identifying a London plane, check the bark as well.

London plane leaf Other leaf, possibly sycamore

Flowers/seeds

Some trees have flowers, especially horse chestnuts, a wonderful sight in spring! Many trees have distinctive fruit, seeds or nuts. However, these only happen at certain times of year and it can be rather annoying if this is all you have for identification! Still, here are some pictures.

London plane seed

London plane seed

Lime or linden flower

Lime flowers

Horse chestnut leaf and seeds

Immature horse chestnut seeds

Go and look at the trees!

The best way to learn to identify trees is to look at real trees. But how do you know what they are? If you are in Cambridge, look at the map and go and look at one of the avenues. There you will find lots of trees, all the same. Look carefully at the trees, the shape, how the branches grow, the leaves, the colours, the leaf shape, the bark, the flowers or seeds if they are there. Then walk around Cambridge seeing how many trees of the same species you can spot!

The Tree Guide of the Woodland Trust gives more information about British trees.