Berkshire Garage Doors: Winter Trees

Just because deciduous trees don’t have leaves in winter doesn’t mean you can’t still have a go at identifying them. In fact, there is quite a science to winter tree identification from terminal twig characters. There are a few field guides out there that can help you on your way but it is best to get familiar with a few basic terms first. So………

This indicates how the buds are positioned on the twig. The point where something happens is called a node. Where one bud arises from the node it would be called ‘alternate’, whereas ‘opposite’ would be used where two buds emerge from the node.

Looking at the buds at the end of the twig can be a useful feature for narrowing down your identification. The most basic form is a terminal bud. This is where a single bud is situated at the end of the twig. Alternate bud arrangements can often end in a false terminal bud. This means that there is a section of twig growing beyond the the final bud. Clustered buds at the tip usually indicate either oaks or cherries.

The bud scales are there to protect the embryonic leaves or flowers contained within the bud. Their number and position can be diagnostic of the genus. For example, willows have only one visible scale, limes have two asymmetric scales and maples have more than four scales always in pairs. The position of the scales in relation to the leaf scar can also be important. Poplars always have a scale emerging directly above the leaf scar.

The leaf scar is the impression left at the point of abscission between the stem and the fallen leaf. It is a very important identification feature. Look out for the shape and position.

Contained inside the leaf scar are the vascular bundle scars. These indicate where the vascular system entered and exited the leaf. Their position in relation to the leaf scar is a key feature to observe.

Some trees come complete with their own armoury. Knowing how to separate the three types of weaponry can greatly help you to narrow down your choices:

Thorns are modified branches and sit above the leaf scar. They are connected to the vascular system of the tree.

Spines are modified leaves and sit below the leaf scar. They are also connected to the vascular system.

Prickles are part of the epidermis, the outer layer of the twig. These are situated anywhere along the twig and are not connected to the vascular system.

Yes, you’ve got it; roses don’t have thorns, they have prickles!

It may seem destructive but taking a linear section through the twig can reveal some clues to the identification of your tree. There are three main types of pith structure. The pith is usually continuous but in some species it can have partitions. These partitions are either segmented (where the areas between partitions are filled) or chambered (where these areas are hollow).

Taking a transverse section through the twig will reveal the shape of the pith. Most are round but sometimes you come across triangular ones, hexagonal ones and even some that are star shaped.