There is something quintessentially English about the bluebell. The sight of a blue carpet spread beneath newly greening leaves in woodland is rarely repeated in the remainder of Europe.
Our native species of bluebell, Hyacinthoides non-scripta, the Common bluebell, is found throughout the Whiteknights campus. In some parts of Britain the species is under threat from hybridisation with the Spanish bluebell, Hyacinthoides hispanica. The hybrid between the two species is fully fertile and sets seed freely. In some woodlands it appears to be out-competing the native species. The hybrid is now believed to be the most common bluebell in urban areas.
Surprisingly the more robust Spanish bluebell is extremely rare on campus – and so are the hybrids. One known area with Spanish bluebells occurs near Upper Redlands Road in woodland that has clear signs of use as a dump for garden rubbish.
All three bluebell species can be found in pink or white versions. These occur as rare natural mutations but are often propagated and sold by the nursery trade. It is quite likely that genetic material of each colour has been introduced onto campus numerous times in the past.
The three species can be separated using a number of characteristics:
Pollen colour:
Common bluebell: cream
Hybrid bluebell: blue with hints of green
Spanish bluebell: pale blue
Flower shape:
Common bluebell: long and narrow bells
Hybrid bluebell: intermediate
Spanish bluebell: short bells, as broad as long
Flower spike:
Common bluebell: nodding flower spike with flowers on one side only
Hybrid bluebell: nodding or partially-nodding flower spike with some flowers on all sides
Spanish bluebell: erect flower spike with flowers on all sides
Leaf width:
Common bluebell: narrow, 0.7-1.6 cm wide
Hybrid bluebell: intermediate, 1-3 cm wide
Spanish bluebell: broad, 2-4 cm wide
Nice post Fay on this loveliest of plants! I think the invasion of Spanish bluebells has I think been exaggerated, as you say it is the hybrid which is the more common non-native in the countryside. The charity Plantlife report on their website that 1 in 6 bluebells is a Spanish bluebell http://www.plantlife.org.uk/wild_plants/plant_species/bluebell but I don’t believe this and I think they are muddling their results of their own 2003 survey which shows 1 in 6 WOODS have Spanish or hybrid bluebells in them, a rather different (and less scary) statistic! People love bluebells and Britain has 50% of the global population so it is important to have an accurate update on the native-hybrid situation in our countryside!