By the path near the orangery and the children's gallery stands a golden rain tree. Its Latin name "Koelreuteria paniculata" comes from an important botanist: Joseph Gottlieb Kölreuter (1733–1806). In the 1760s, he was director of the court gardens in Karlsruhe.
The leaves turn yellow and orange in the fall.
The genus Koelreuteria comprises three species of woody plants in the sapindaceae (soapberry) family. They originated from East Asia. A golden rain tree, Koelreuteria paniculata, can be viewed at the Karlsruhe Botanical Gardens. It is also known as the China tree. Its leaves are similar to those of an ash tree and turn stunning shades of yellow and orange in the fall. In July and August, it develops 40 cm long loose branching clusters of yellow flowers.
A unique feature of the golden rain tree is its green fruit, which is shaped like a Chinese lantern or bladder, hence its German name meaning bladder ash. But the tree has further significance for the Karlsruhe Botanical Gardens: Its Latin name, Koelreuteria, comes from influential botanist Dr. Joseph Gottlieb Kölreuter, who was the court garden director at Karlsruhe under Margrave Karl Friedrich von Baden between 1765 and 1769.
Dr. Joseph Gottlieb Kölreuter.
Kölreuter was particularly interested in plant pollination. In 1760, he won a competition in St. Petersburg on the question of plant gender. He offered definitive proof. His achievements in hybridization made him a pioneer in the field of plant genetics. His multi-volume writings on "Vorläufige Nachricht von einigen das Geschlecht der Pflanzen betreffenden Versuchen" [Preliminary report on several experiments related to plant gender] were published between 1761 and 1766.
At the Karlsruhe Botanical Gardens, at Margravine Karoline Luise's special request, Kölreuter arranged the plants based on the botanical system created by Swedish botanist Carl von Linné among others. The gardeners at Karlsruhe apparently had little appreciation of his botanical experimentation. He quit his position after four years due to disputes and continued his research in private. He died in 1806 in Karlsruhe. The golden rain tree stands in his memory to this day.
