17th May 2024
Following last month’s article on Wild Garlic so many people have asked “what about Bluebells?” I decided to make a special to visit one of our beautiful local bluebell woods; why not do the same but be quick as the flowers disappear as quickly as they arrive!
Bluebells (Hyacinthoides nonscripta) transforms our woodlands in springtime. That carpet of intense blue under the opening canopy is one of our greatest woodland spectacles.
It is also a British specialty, with the UK home to 50% of the world’s population and often indicates a site of ancient woodland. Bluebells propagate not by producing daughter bulbs like daffodils, but predominantly by seed. Each germinating seed takes five years to grow into a flowering plant, with bulbs lasting up to 60 years.
Have you ever wondered, how they are in their flowering prime when so many other plants have only just started to grow? Bluebells have several tricks up their sleeves, including co-operation with fungi known as mycorrhiza. This allows them to extract phosphorous from the soil, important for growth, while at the same time depriving their competitors of the same essential nutrient. They also have an unusual way of storing their energy. Most plants use glucose and build starch or cellulose. Bluebells predominantly converts sunlight, carbon dioxide and water by photosynthesis into fructose and builds fructans (a chain or polymer of fructose molecules). This adaptation allows bluebells to photosynthesise at temperatures below 10 degrees Celsius, which has been useful in the recent cold wet spring. The bulb comprises of 70% fructans, which then fuels its early growth in late winter.
However, despite all these tricks, our native bluebells are under threat, not from the Spanish Bluebell as most people believe, but the love child or hybrid between its British and Spanish parents. Like some children, it has caused problems. The hybrid bluebell was first recorded in the UK in 1963 and having “hybrid vigour” has spread quickly and enabled it to out-compete our native Bluebells. Hybrid Bluebell is fertile and able to back-cross with either parent to form a complete range of intermediates, producing a ‘hybrid swarm’ and diluting the gene pool.
Native Bluebell (Hyacinthoides non-scripta):
Narrow linear leaves (7-15mm wide)
Flower spike 1-sided, drooping at tip. The flowers typically all hang down.
Individual flowers are parallel-sided tubes, with strongly curved tips.
Anthers have white-cream pollen grains.
Spanish Bluebell (Hyacinthoides hispanica):
Broad linear leaves (10-35mm wide)
Flower spike erect, flowers are not one sided. Looking not dissimilar to cultivated Hyacinth.
Individual flowers bell- or even saucershaped, broadening towards tip.
Anthers when first open have blue pollen grains.
Hybrid Bluebell (H. massartiana): A mixture of features from both parents, but more likely to resemble the Spanish Bluebell. This is the commonest bluebell found in gardens.
Bluebells are poisonous if eaten, unlike Wild Garlic and contain toxic biologically active compounds to defend themselves from being eaten by animals and insect pests. Scientists are now actively researching these chemicals to see if any can be used to treat cancer.
However, our ancestors found plenty of uses. The sticky bluebell sap was used to bind pages to the spines of books and stiffen the ruffs of Elizabethan collars and sleeves. As far back as the Bronze Age, people were using the sap to set feathers upon arrows, known as fletching. Giving us the surname ‘Fletcher’. If you have any Bluebells growing in your garden (native or non-native) you can test the adhesive qualities of the sap. Carefully dig up a bulb, wash off the soil and cut the bulb in half. Squeeze out a little sap and press firmly onto a volunteer’s forehead. Just as ‘Dr Who’ returns to our screens, you have my version of a botanical Dalek!