Hawthorns

Midland Hawthorn, Crataegus laevigata, and Common Hawthorn, Crataegus monogyna.
Sevenoaks Wildlife Reserve, 25 April 2017.

Most of the hawthorn bushes we see in the south of England are the Common Hawthorn, Crataegus monogyna.  The bush in the middle distance of this photo is one.  In the foreground is a less common species, a Midland Hawthorn.  Its flowers are just a little more showy than the common sort.  Also, the leaves are in general much less divided.  But this is not the best way to tell them apart.

Midland Hawthorn, Crataegus laevigata, and Common Hawthorn, Crataegus monogyna. Flowers compared.  25 April 2017.

Common Hawthorns have just one stigma in the centre of each flower, and just one seed in the berry later on.  Midland Hawthorns have two or sometimes three stigmas, and two or three seeds in the berry.

Counting stigmas or pips is the only real way to be sure of these.  Because, as is so often the case, you might also come across a hybrid between these two species, Crataegus x media, which has leaves and flowers intermediate between them.  So on the hybrid, the flowers have mostly one, but sometimes two stigmas, and the pips in the berries follow suit.  Here is one we found in May last year:

Hybrid Hawthorn, Crataegus x media.  C. monogyna x C. laevigata. Near Jail Lane, 21 May 2016

They're common in some places, but often under-reported in the wild because not everyone goes around counting stigmas on hawthorn bushes.  I am told that they have been used in hedging because they are robust, but I have never found the common C. monogyna to be less than vigorous. 

Counting stigmas is MUCH easier than counting the pips, so this is the time of year to look for Midland or hybrid hawthorns them if you are so inclined.  Coloured and double-petaled forms of the hybrid are sold as garden shrubs.