Plant ID Week 8: Winter twig identification

The very last Plant ID session was on winter twig identification. When identifying trees and shrubs not in leaf, one has to rely on other features for identification, such as the colour, texture, size and positioning of buds, bark colour, twig shape and structure and so on. Once you know what to look at, twigs that looked very similar will resolve to look quite distinctive.

The Woodland Trust have an excellent twig identification sheet which can be downloaded from here. It covers all our twigs barring Malus sylvestris, and the below images are from there (clicking on an image lets you view it in full size).

(Field maple (Acer campestre) isn't on our list)

Note catkins on alder (Alnus glutinosa)
and hazel (Corylus avellana).

Note difference in hawthorn (Crataegus monogyna)
 and blackthorn (Prunus spinosa) bark texture.

Here's our full list of winter twigs, with identification information:

Malus sylvestris twigs. Note the abruptly finishing shoots.
(Source)

Tilia x europaea bud detail. Note the mitten-like shape.

Aesculus hippocastanum twig detail showing
the horseshoe shaped leaf scar.

Reflection:
There are a large number of online winter twig identification keys of various quality and usability. If choosing to use one, you should first of all check where in the world it applies to - a North American key would be of limited use in Ireland. Additionally in the horticultural trade we're not limited to native and naturalised trees, but will also need be able to distinguish any number of deciduous shrubs around the year. Here experience will be the best teacher.

One last thing to keep in mind is to not just look at the tips of twigs when identifying a deciduous specimen: the shape and general habit of the tree can be as important an identifying feature. For example, I'm reasonably sure these are Carpinus betulus 'Fastigiata', the upright elm, a popular modern street tree, just by their shape.