The sheet illustrates twigs of common trees in the British countryside. It was used during the GNS Zoom members’ meeting on 20 January 2021. The twigs are arranged so that twigs with similar features are close to each other.
Thus, both elm and field maple often have very ridged bark on quite small twigs, but the buds on an elm twig zigzag along it, whereas field maple buds are opposite each other.
Sycamore is another member of the maple family, and it shares the feature of buds opposite each other, but its buds, especially the end one, are much larger and usually bright green.
Another twig with opposite buds is ash, but in this case the buds are sooty black (ash – sooty – get it?).
Willows are very confusing, with twigs in a range of colours often with buds in a matching colour. If you look closely you will see there is just one scale covering the bud, which comes off as a single unit when the bud bursts in spring. Lime twigs can look quite like willow, with the twigs often coloured red on the sunny side, but the buds are placed zig-zag fashion. The buds of lime are often a rich red, and each bud has a covering of two or three bud scales which are different in size to each other making the bud look a bit like a mitten.
Both oak and cherry can have clusters of buds together on the end of twigs with side buds spiralling up the stems. You may see long extension twigs on cherry with more evenly spaced buds and just two or three at the top. If in doubt, look at the ground because oak leaves are very tough and will survive the winter intact. Cherry leaves are less durable but you may be lucky.
From a distance a walnut tree can look quite like ash. Walnut has dark buds, but they are not opposite each other. In walnut the leaf scar, where the previous year’s leaf stalk dropped off, is a bit like a monkey’s face, broad, with the marks of the vascular bundles looking like two round eyes with a smiling up-turned mouth below. In ash you just get the smile. Another fun clue to walnut is that the twigs have laddered pith, which is a rare feature not found in other common trees in the British countryside. There will always be twigs on the ground that can be split to check.
The twigs of sweet chestnut are rough, unlike the silky smoothness of lime, for example. The sweet chestnut leaf scar is offset at the side of bud, not directly below it which is the more normal placement.
In poplars the buds spiral up the stems, but the side-buds sit directly over last year’s leaf scar. The illustration is of a twig with leaf buds, but beware that in poplar, and indeed in many trees, flower buds can look very different, much larger and rounder. In poplar, at least, they are often on little side-shoots. The balsam poplars are easy because the buds are sticky and smell strongly of sun-tan lotion. Poplars sucker, so you will often see young stems coming up in the field 50 yards or more away from the parent tree, and they can
grow fast – more than 6ft in a year.
Beech separates out easily because the buds are very long and pointed, zigzagging up the twig and sticking out at an angle of more than 45 degrees. Hornbeam buds are pressed tight up against the twig, sometimes with the tip curving inwards. Both beech and hornbeam can retain dead leaves on lowest branches over the winter, especially as hedges, but the angle at which the buds are held will easily differentiate them.
This is an introduction to get you looking at some of the important features. There will be plenty of exceptions and of course many more species to examine. For rigour, consult John Poland’s The Field Key to Winter Twigs (2018).