The university's Botanical Garden is full of hidden treasures. There are interesting stories surrounding many of the plants - such as the pretty columbine, the thorny holly or the exotic New Zealand flax. On a guided tour for university staff, Klaus Bernhard von Hagen shows the most beautiful corners.
What does Harry Potter have to do with the evergreen holly? Fans know: Harry's wand is made from the wood of the bush, which is also known by its scientific name, holly. Dr Klaus Bernhard von Hagen explains why Joanne K. Rowling selected this particular plant for the hero of her story: "The holly is one of the few evergreen plants in this country and is considered a symbol of life." So it's no wonder that Harry Potter, "the boy who survived", has a wand made of holly.
Other plants in the publicly accessible part of the Botanical Garden on Philosophenweg also have a magical connection. Von Hagen demonstrates, for example, that the pollen of common pines and the spores of ferns are as explosive as flea powder. In Rowling's novels, wizards throw this substance into the fire in order to travel through the area via a network of chimneys. Although fern spores do not transport anyone to another place, they can be used to great effect in fire shows. They are as explosive as flour dust, reports von Hagen. To demonstrate this, he lights a garden torch, takes a handful of spores and throws the powder towards the flame. For a few seconds, a fireball the size of a football lights up - which quickly disappears again without causing any damage.
The secret of the mandrake
We continue to the medicinal garden, where a mandrake grows. "The magic plant par excellence," says von Hagen. With its rosette-shaped leaves that have been punctured by snails, this plant does not give any hint of magical powers at first glance. However, all parts of the plant are highly poisonous, and eating it causes intoxication and can even lead to death. The bizarre shape of the long roots has probably contributed to the creation of the myth. "They often look like a person without a head," reports the botanist.
Wondrous stories are also associated with some of the mandrake's neighbours in the flowerbed - such as lungwort, lady's mantle and horsetail. These plants stand together because they have a similar history. They are so-called signature plants, to which - mostly in the Middle Ages - a healing effect was attributed due to their shape, smell or colour: Lungwort, for example, whose spotted leaves resemble a lung, is said to help against respiratory diseases. The round leaves of lady's mantle are reminiscent of a cloak in medieval depictions of the Virgin Mary, which is why it was assumed that the plant could alleviate women's ailments. "The doctrine of signatures is still widespread in esoteric circles, but lacks any scientific basis. The vast majority of these plants are not medicinal," reports von Hagen.
Symbols in the petals
The columbine, "a beautiful but sometimes annoying plant in the garden", as von Hagen says, combines several Christian symbols. With its three-part leaves, the plant from the buttercup family symbolised the triune God in the Middle Ages. The columbine's petals, on the other hand, are reminiscent of doves - the symbol of the Holy Spirit. The tips of the five petals can also be joined to form a pentagram, also known as the Druid's foot, a symbol that appears in many contexts and stands for the five wounds of Christ, among other things. The columbine was therefore long regarded as a healing plant and can be found in many medieval paintings and images of saints.
The Botanical Garden is not just for Harry Potter fans and friends of symbology. There is something for everyone on the 3.7 hectare site. Students can memorise the family tree of plants and the most important characteristics of the various plant groups on a living object, while children will love the hobbit cave in the New Zealand section and the aquarium with the axolotl - a newt from Mexico with the unique ability to regrow lost limbs. Lovers of the Mediterranean can enjoy a southern flair in the Mediterranean garden, while school classes can experiment in the Green School.
Stinging nettle - a vitamin bomb
Among the more than 4,000 plant species in the Botanical Garden are not only record holders such as the mighty giant sequoia or the New Zealand flax, whose sword-shaped leaves can withstand amazing tensile forces. Even commonplace plants reveal unexpected qualities on the Philosophers' Walk. Take the stinging nettle, for example: its sturdy fibres are now regarded as the textile material of the future, the astonished visitors learn. Vegetarians have also discovered the weed as a vitamin bomb. Von Hagen demonstrates how to touch the leaves at the base so as not to come into contact with the dreaded stinging hairs. He carefully takes a leaf between his fingers and then moves them towards the tip of the leaf to render the stinging hairs harmless. He folds the leaf a few more times - and puts it in his mouth. "Tastes like spinach," he says, and hands out more tasty morsels.
Of course, visitors should not light fires, tear leaves off the Botanical Garden's plants or eat any parts of the plants. After all, quite a few of them are poisonous. However, a visit to the green outpost of the university is always worthwhile - for example on the show day. This year, it takes place on Sunday 17 June and is all about pharmaceutically active plants. There will also be a varied children's hands-on programme, catering and much more.
