From acid to alkali

19th April 2013

The two species of Sorrel we featured over the last two days are both lovers of neutral or acidic soil and Sheep’s Sorrel particularly will not tolerate alkaline soil.

Both of these were found in the same woodland lying on the Greensand Ridge.  This remnant of the last ice age, is band of sand deposited on top of the underlying chalk and clay of central Befordshire by glaciers and is famous for providing ultra fine silver sand and sand for building from the quarries in Leighton Buzzard.  It also gives rise to acidic soil conditions and so creates quite rare habitats such as heathland, acid grassland and acidic wetland areas, which are all quite rare for this part of the UK. These areas will host some quite specific acid loving plants which are found nowhere else in the county such as Lily of the Valley, Small-leaved Lime and Black Popular.

However, travel south just 10 miles or so and you reach Dunstable Downs an area of chalk downland which forms part of the Chiltern hills which extend away to the south-west.  The soil conditions here are distinctly alkali and this will give rise to a completely different mix of plant species which includes Cowslips, Common Spotted Orchid, Dropwort etc.

At the moment Sweet Violet Viola odorata is in full flower and this is generally a plant of alkali and particularly chalky soil and its purple or sometimes white flowers can be found scattered among the grass on the slopes of the downs.  There are several species of Violet that grow in the UK, the commonest being the Dog Violet V. canina which is found in woodland and also flowering at the moment but also several other species. All are edible, both leaves and flowers, however it is only the Sweet Violet whose flowers have a scent and taste. That taste and smell is what gave the old fashioned Parmar Violet sweets their distinctive  flavour for those who are old enough to remember them.

Sweet Violet Viola odorata Violet form

and the white form
The flavour can be used to infuse into syrups or simply flavour sugar by layering the flowers with layers of sugar. The can be used in jellies and sorbets and also crystallised and used as a garnish.

In Heston Blumenthal’s restaurant, the Fat Duck they serve Violet Tartlets…..pastry filled with a Violet caramel topped with a single crystallised violet flower.

The leaves too, are edible either raw in salads or cooked as a vegetable.


Kev Palmer

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