Stanmore Country Park Nature Trail
Post 13: The spiky bush is the midland hawthorn Crataegus laevigata. Botanists can distinguish the midland hawthorn from the more widespread common hawthorn Crataegus monogyna by counting the styles; it has two styles per flower where the common hawthorn has one. An easier way is to pick ten or so fruits and, squashing them between your fingers, count the number of seeds in each fruit. A pure midland hawthorn will have two seeds per fruit; a pure common hawthorn will have one. Hybrids are common and will have a seed per fruit average between 1 and 2. The leaves differ: common hawthorn leaves tend to be more deeply divided than those of the midland hawthorn – see illustration below. However, leaves of all shapes can be found on a single bush, so leaf shape is a poor method for distinguishing the two species.

As you continue up the hill you pass though woodland of oaks with a few birches. Until the Second World War this area was open fields separated by hedges; when grazing stopped after the war secondary woodland grew up. All the trees you see here are therefore under 60 years old.


Image: Typical leaves of common hawthorn on the left, and midland hawthorn on the right. Image by Steve Bolsover.

To description for post 14

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