Monday, May 14, 2012

Bluebells, native and introduced

click photo to enlarge
It is estimated that between a quarter and a half of all bluebells (Hyacinthoides non-scripta) are found in the British Isles. In England they are a much loved flower, and a visit to a "bluebell wood" in April or May is a pleasure that many seek out in spring. The carpet of blue flowers taking advantage of the filtered light through the emerging tree canopy is one of nature's finest sights. However, the native bluebell is under threat from loss of habitat, illegal picking (they are protected by law) and hybridisation. Moreover, I am one of those who is contributing to the decline of this beautiful flower.

How so? When I moved to my present house I enjoyed the appearance of bluebells in the garden each spring. Clumps grow under the willow tree, fruit trees, flowering cherries, maple and in the deep borders shaded by silver birches and shrubs. They grow on our rockery too. But, I discovered, these are not the native bluebell, they are mostly the Spanish bluebell (Hyacinthoides hispanica) that is commonly found in gardens and sold in garden centres. A few are hybrids produced by the natural crossing of the native species with the Spanish variety. Such has been the impact of this introduction and hybridisation that the introduced bluebells are increasingly common in the countryside and few urban or garden bluebells are the native species. How can you tell the difference between H. non-scripta and H. hispanica? The native flower is scented, the anther that bears the pollen is cream coloured and the flowers are carried only on one side of the stem. In the non-native species there is no scent, the anther is mid-blue and flowers are carried on all sides of the stem. The hybrid, Hyacinthoides x massartiana is more like the Spanish variety but has creamy-blue anthers.

There is no easy answer to the problem of how to ensure the survival of the native bluebell throughout the country. It may be that the best we can hope for is its survival in more remote woods. It would seem that the spread of the Spanish variety and the hybrids is well past the point where eradication is a feasible solution. Lincolnshire has bluebell woods, but in the Fenland region the flowers are found in smaller stands of trees, gardens. These bluebells in Swineshead churchyard (churchyards are another common location for the flower) hint at the beauty they bring in spring, but are, you've guessed it, further examples of the non-native flowers.

photograph and text (c) T. Boughen

Camera: Lumix LX3
Mode: Aperture Priority
Focal Length: 5.1mm (24mm/35mm equiv.)
F No: f4.5
Shutter Speed: 1/800
Exposure Compensation: -0.33 EV
Image Stabilisation: On