This plant is not yet visible in the Garden.
Immortalised by the song from The Sound of Music, Edelweiss is an Alpine flower in the Daisy family (Asteraceae). The ‘flower’ is a combination of tiny composite heads of yellow flowers and longer, furry ‘bracts’ – modified leaves which the plant uses for display. The appearance of the furry bracts is the reason for the plant’s Latin name, Leontopodium, which means ‘lion’s paw’.
Edelweiss lives in rocky ground at altitudes of between 1,500 and 3,000m above sea level, where levels of UV light are higher than at ground level. UV light causes sunburn in humans, and in plants can cause damage in a similar way. Edelweiss has evolved hairs which the plant uses as its own natural sunscreen: the hairs completely absorb UV light, protecting the living cells beneath from being damaged. These hairs could inspire new types of UV-protective materials for packaging or industrial paints, which currently mostly rely on UV-reflecting ‘nanoparticles’ – tiny beads that are hard to handle.
A note on the microscope picture: finding an electron microscope picture of Edelweiss which we were allowed to use proved difficult. Writing this trail in January, we did not have fresh specimens to hand which we could use to take a picture ourselves, so we turned to the University Herbarium for help. A Herbarium is a collection of dried, pressed plants, and the University is fortunate to have an enormous collection of over a million specimens, including several Edelweiss. Dr Lauren Gardiner, Curator of the Herbarium, kindly allowed us to take a small sample of one of the flowers for analysis. See the image below for the sheet containing the specimen used for the microscope image; it was collected in August 1881 by Charles Packe in the Malibierne rocks, south of the mountain of Maladeta in the Pyrenees. Packe was a noted climber and mountaineer, who also practised botany and geology. One can only imagine what he might have thought of his specimen being used nearly 140 years later to educate visitors to the Botanic Garden.