Thursday, April 05, 2012

Bee-friendly Plant of the Month - the Bluebell

The British flora, although small by global standards, is interesting for being a mixture of the floras of several northern temperate zones. In the north of England and the mountains of Scotland, an arctic-alpine flora found more widely across Scandinavia reaches its southernmost limit. In the extreme south of England, Mediterranean species such as the early spider orchid reach the northern edge of their range. But where the British Isles come into their own is in the case of the so called Lusitanian flora.


Named after ancient Portugal, this flora is made up of species that favour the mild, damp climate of the western European Atlantic seaboard. Many of the plant species characteristic of this flora are quite obscure; the strawberry tree of southern Ireland, the pale butterwort of West Country bogs. But one species is an icon of the British landscape. The native bluebell (not to be confused with the Scottish bluebell, which is a harebell!) is found from Spain and Portugal up through France and into Belgium and Holland. But nowhere other than the UK does it form the vast, glowing blue carpets familiar from our ancient woods. And ancient woodlands are the place to find it; a poor disperser, it rarely colonises new sites, instead lying dormant as seed in the soil or growing vegetatively in the shade until a gap in the canopy lets in light and triggers the spectacular display of mass flowering. It will even hang on for years in fields where woodland has been felled, a ghostly reminder of an historic landscape. 


The bluebell’s inability to colonise is something that is sadly not shared by its close cousin, the Spanish bluebell. This rather more robust plant, often grown in gardens, is a superlative escape artist, and is turning up with depressing regularity in the wild, often from dumped garden waste. More insidiously, its pollen is carried by bees and other insects which then fertilise native bluebells. The resulting hybrids then out-compete their pure-blood cousins, spreading their genetic influence ever wider. My advice would be to avoid it as a garden plant; it lacks a lot of the charm of the native species anyway.
Another threat to the native bluebell has been large-scale digging up of bulbs for sale, but it is now protected by the Wildlife and Countryside Act and it is illegal to sell bulbs or seed of wild bluebells.


Our native bluebell has undergone several changes of scientific name as taxonomists wrestle with its place in the plant kingdom. It is closely related to the squills (Scilla), of which there are two species native to the British Isles. Like their larger relative, both Spring and Autumn squill are found along the west coast, usually in short, open turf on cliffs, where they can form carpets of violet-blue.

No comments: