Fern House
At higher altitudes in the tropics and subtropics, it is by no means tropically warm. Here, precipitation is extremely high and the mean annual temperature at 2,500 meters above sea level is only 16 degrees Celsius. It is the home of the cycads.
Mountain rainforests
Here, temperatures fluctuate significantly, not only during the year but also during the day. Humidity almost always reaches 90 percent. All this causes a very characteristic development of the vegetation. Trees do not grow so tall, and the tree ferns predominate.
Seven different species of these stately and magnificent ferns are cultivated in the Botanic Gardens of the University of Bonn (the genera Cyathea and Dicksonia).
The soft tree fern (Dicksonia antartica) grows very slowly, 5 cm a year at most. Its fronds grow to 4 meters long. In recent years, the soft tree fern has become a popular ornamental plant in our country. Because it grows so slowly, it is not worth propagating. The plant was simply dug up in the woods in the natural habitat. As a result, it is now endangered in different locations.
Tree ferns provide a place with great light exposure for many species of epiphytes.
Boat orchids
In the fern house, the many colorful jewelweeds (Impatiens) and the magnificent orchids catch the eye.
One of them is the Low's boat orchid (Cymbidium lowianum). Cymbidium species are native to Asia and northeastern Australia. Even Confucius (551-478 BC) admired the splendor of these orchids.
Today, Cymbidium hybrids are offered everywhere in large quantities and even sold in supermarkets.
Pure species, like Cymbidium lowianum are considered rarities.