Tuesday, 21 April 2020

Bluebells... or are They?
Bluebells at Garston Wood on 8 May 2000 by Steve Day

Bluebells... or are They?

May was always the traditional month for bluebells. Not now. They first appeared at the end of March this year and now the woods are full of them in full flower, and it is still well before the end of April.

Bluebells grow in swathes in moist woodlands. In common with other early spring flowers they are rich in pollen and nectar. They are an important source of food for insects, especially bumblebees, their chief pollinator. They are one of the most arresting sights of spring; their colour glows out from under the trees, particularly in dull weather when they are not bleached by sunlight.

The true native British bluebell (Hyacinthoides non-scripta) is a charming plant. Its narrow bells are all arranged on one side of the stalk and it has a graceful curve to its stem. The Spanish bluebell (Hyacinthoides hispanicus), by contrast, is a sturdier-looking upright plant with its bells arranged all around the stem. This altogether coarser plant was introduced to British gardens by the Victorians and can now be found growing in many locations, such as roadside verges or woodland edges, mingling with the native plants.

If you look into the flower of the native bluebell you will see that the pollen on its anthers is creamy white and this is one of the main features that distinguishes it from the Spanish bluebell, where the pollen is blue or greenish. It's important to look at the most newly opened bells at the top of the spike to check this feature because once the pollen is shed the anthers on the Spanish plant can appear whiteish.

Another difference is in the shape of the bells: the narrow bells on the native species are very noticeable once you take a good look, and are tightly rolled back, whereas in the Spanish bluebell the bells are wider and more flared and less rolled back at the tip. They also lack the sweet smell of the native bluebell. The Spanish bluebell also tends to be a much paler blue and the plant has wider, fleshier leaves than the native.

The situation is complicated by the fact that the two species hybridise readily. In many places it is difficult to find a pure native. Hybrids come in many forms with a whole range of intermediate characters. Some have from half to all the bells surrounding the stem, some droop a little, some have narrow leaves, others have white pollen, and so on, often making it difficult to determine the true native from the hybrid without genetic testing. However, native white bluebells are extremely rare and pink ones are not known to exist so if you see a white or pink flower the plants are probably hybrids.

Growing naturally in Atlantic areas from north-western Spain to the British Isles, Britain has up to half of the world's total bluebell population, which is relatively rare in the rest of the world. One cheering fact is that scientists have discovered that according to genetic tests the native bluebell is more fertile than the Spanish or its hybrid, so that Hyacinthoides non-scripta is not in danger of disappearing. The woods are safe for now!

Juliet Bloss, April 2020