Why Leaves Make the Best Starting Point

A hedgerow is rarely a tidy row of one species. It is usually a jumble of seedling trees, coppice regrowth, saplings and ancient stools, sometimes flailed into a tight, prickly mass. Flowers are gone by high summer, berries are months away, and bark on young growth is notoriously variable. Leaves, on the other hand, are right in front of you from late April until October, and they carry a great deal of dependable detail.

You do not need to name everything. Learn a dozen common hedgerow trees properly and you can read most British hedges with real confidence.

Whole Leaf, Not Just Blade

Before you look closely at the leaf itself, check how the leaves are arranged on the twig. This one habit will save you more time than any other.

• Opposite: leaves in pairs on the same node, one each side. Field maple, ash, elder, spindle and dogwood do this.
• Alternate: leaves stepping up the stem one at a time. Hawthorn, blackthorn, hazel, holly, oak, rose and bramble.

Then decide whether the leaf is simple (one blade), lobed (one blade with deep indentations), or compound (several leaflets on one stalk). Hawthorn and field maple are lobed but not closely related — hawthorn leaves are alternate, deeply cut with three to five lobes, and glossy dark above. Field maple leaves sit in opposite pairs, are smaller, five-lobed, with blunt, rounded lobes and shallow gaps between them. Snap the leaf stalk and field maple gives a drop of milky sap.

Reading the Leaf Edge

Run a finger along the margin, then look properly. Edges fall into a few useful groups.

• Entire: smooth all the way round. Spindle and holly are the ones to know, though holly adds spines on lower leaves and often loses them higher up a mature tree.
• Singly toothed: a neat row of teeth, each one separate. Blackthorn and dog rose fit here.
• Doubly toothed: each tooth carries smaller teeth along its own edge, giving a slightly ragged look. Hazel and wych elm are classic examples, and both feel soft and rough at the same time.
• Jagged and coarse: bramble, with three to five leaflets, hooked prickles and a pale, whitish underside.

Veins, Stalks and the Underside

Once the shape is clear, the finer furniture clinches it. Pinch a leaf over and look at the underside, holding it up to the light if the sky is bright.

• Pinnate: leaflets in pairs along a central stalk, with one at the end. Ash, elder, rowan, dog rose and bramble.
• Ash: opposite, seven to thirteen leaflets, teeth only along the upper part of each leaflet.
• Elder: opposite, five to seven oval leaflets, sharply toothed, and an unmistakable rank smell when crushed.
• Oak: rounded lobes — never pointed with bristle tips, which would point you towards a different tree entirely. Common oak leaves have little ear-like lobes at the base and a very short stalk. Sessile oak has a longer stalk and a tapered base.
• Wych elm: the two sides of the leaf base meet unevenly, one side running further down the stalk than the other. This asymmetry is the quickest elm clue there is.

Stalks matter too. Hazel leaves are round with a heart-shaped base, softly hairy, with strongly pressed veins. They are often on coppiced stools with many stems from one point.

Where a Hand Lens Earns Its Keep

A 10x hand lens in your pocket turns a good guess into a certain identification. Three things are worth checking at magnification.

First, the vein axils — the little junctions where side veins meet the midrib on the underside. Common oak carries tufts of tiny hairs there; sessile oak does not. Second, the exact tooth pattern, which is far more obvious under glass than to the naked eye. Third, hairs on the underside and along the midrib, which separate species that look otherwise identical from arm's length.

Glands are another lens job. Bird cherry, occasional in old hedges, has a pair of small red glands on the stalk just below the blade.

Spring and Summer in the Hedge

Young leaves are unreliable. Fresh May growth is smaller, thinner and often incompletely toothed, so give a hedge until late May or early June before you trust it. Work along a stretch of hedge rather than one bush, and sample leaves from the middle of the canopy, not the flushes on top of a laid or flailed section.

By July, leaves are fully formed and the differences are crisp. Take a notebook, sketch the outline rather than photographing everything, and press one leaf of anything puzzling. A short walk with a lens and a pencil will teach you more than an hour of scrolling ever will — and the slow pace is half the pleasure.