Object of the Month 05/2023
Goethea, native to Brazil, belongs to the mallow family (Malvaceae). It forms a weakly branched shrub that can grow to about 2 m high. The more than 20 cm long stalked undivided leaves sit singly on the woody shoot. The arrangement of the flowers is special because they are stem-flowered (cauliflorous) on very short generative side shoots. These side shoots grow only slowly and produce new flowers again and again, especially in the light-rich season. The flowers themselves are very attractive due to red sepals as the actual display apparatus. Goethea finds use as a flowering pot plant in normally heated rooms and can last a long time with good care and suitable site conditions.
Nees von Esenbeck described the genus Goethea for the first time in 1821. Together with C.F.P. Martius he paid tribute to the great German poet, naturalist and botanist Johann Wolfgang von Goethe, which can be seen in his letter to Goethe from 24.06.1820.
Currently there are 6 different species (https://www.tropicos.org/), 2023). The species present in the HU collection was first presented scientifically in 1852 by William Jackson Hooker in the Botanical Magazine. The actual plant material of the collection originates from 6 cuttings, which were provided by the Botanical Garden Leipzig for research purposes on 20.08.1993. Subsequently, first investigations on the suitability of this plant species as a novelty for the ornamental plant assortment started at the then Department of Ornamental Crops of HU-Berlin.
In the course of time, several graduation theses by students as well as publications on selected research topics could be written. Plants from the collection were also presented with appropriate descriptions at plant fairs (e.g. the International Plant Fair in Essen) or at exhibitions in Frankfurt am Main and Bonn on Goethe Festival days.
Selected research topics during the time in the collection.
- Research on vegetative propagation by cutting selection and its effects on subsequent growth.
- Research on flower formation and development, growth rhythms
- Research on branching, generative side shoots and tip promotion
- Search for optimum values with regard to light and temperature
- Post harvest during transport, storage and shelf life/reflowering at the end user
- Studies on leaf deformations
Plant care at the consumer
Goethea is a typical warm-house plant, which is best placed in normally heated living rooms by a bright window. The plants need sufficient water and nutrients, especially in the light season, and in summer it is necessary to fertilize every 14 days with a balanced complex fertilizer liquid 0.2%. In winter, fertilization every 3 weeks is sufficient. Waterlogging is generally to be avoided, otherwise leaf lightening (chlorosis) may occur. Propagation is possible by cuttings. Pests can be spider mites, especially in winter when the plant is dry in the air. Larger plants can tolerate pruning down to a third of their original size. Lower leaves can be removed to make the flowers more visible.
By PD Dr. Heiner Grüneberg
Tropical and Subtropical Ornamental Plants: https://www.sammlungen.hu-berlin.de/sammlungen/tropische-und-subtropische-zierpflanzen/