The Titan Arum, native to Sumatra, is one of the most spectacular phenomena in the plant kingdom; it was discovered in the 19th century by the Florentine botanist Odoardo Beccari (1843-1920). In the course of an expedition in the Atjer Mantior on 6th August 1878, he was able to observe the leaves and fruits of a plant, and, on 5th September he saw a flowering plant. Beccari sent a few tubers and seeds to Florence. The tubers all perished, but a few seeds germinated, and some were sent to Kew Gardens. There, in 1889, 11 years after its discovery, a plant flowered for the first time outside its tropical home country. It was in the November of 1878, the year he discovered the plant, that Beccari made his extraordinary find known in the Gardeners' Chronicle naming the plant Conophallus titanum. In 1879, the plant received its current scientific name Amorphophallus titanum (Becc.) Becc. ex Arcang.
Description and natural habitat
As displayed on the following drawing, the plant has an underground tuber, which can weigh up to 75 kg. This tuber produces a single, multipinnate leaf, which can grow up to 6 m tall and nearly as wide. This leaf lives for 9 to 24 months and, during its lifespan, it delivers the energy for a new, larger tuber. At irregular intervals of several years, instead of a leaf, the tuber produces a colossal inflorescence, which can grow more than 3 m high and 1.50 m wide.
In the biological sense, this inflorescence represents a flower - the largest in the entire plant kingdom. The tiny individual male and female flowers of this inflorescence are located at the base of inflorescence (the spadix) and are surrounded by a gigantic spathe. The shape, dark brownish-purple colour and their bad carrion smell, the plant imitates a rotting animal carcass, thus attracting small nocturnal bugs (Carrion bugs like Diamesus spec. and the short-winged Creophilus spec.) as well as bees (Hetterscheid 1998). The animals crawl across the funnel-shaped spathe or the upright spadix into the inflorescence, in order to deposit their eggs. In this process, they transfer the pollen and thus pollinate the plants. When the bug larvae hatch, they starve as their parents were fooled by the titan arum. For this reason, plants that do not reward their pollinators are called deceptive. The infructescence can also grow as tall as 2 m. Its berry fruits, which contain two seeds and are 4 to 6 cm long, are bright red and are probably distributed by hornbills (Buceros spp.) (T.M.Everett, Journ.N.Y.Bot.Gard. 1955).
The Titan Arum is only native to the Island of Sumatra (Indonesia), where it can be found in the undergrowth of rainforests on chalky soils. However, it only seems to flower in clearings, open patches or alongside roads.
The Titan Arum in cultivation
Titan arums are a rare sight in botanic gardens. Worldwide, about 70 plants have flowered in gardens since their discovery. Flowerings in Germany have only been reported from Bonn, Hamburg, Leipzig, Mainz, Munich, Stuttgart and the Palm Garden in Frankfurt (here, there have been about 20 flowerings since 1992). Its cultivation is very difficult as its giant tuber is very susceptible to nematodes, which can destroy it. Most flowerings were from plant tubers directly imported from Indonesia, and in the majority of cases, the plants died after flowering as the tubers had already been infested with nematodes on arrival.
In Frankfurt, Professor Kohlenbach approached the issue from a different angle, by propagating Titan Arums in tissue culture. This means that in a laboratory, plants are grown under sterile conditions. By this method, he obtained 33 plants which were distributed to botanic gardens, Bonn being among those who received a plant. In 1994, the first of these plants flowered in Mainz and here in Bonn in 1996 and 2000 from Professor Kohlenbach's material.
All about the cultivation of Titan Arum
Lobin, W., Neumann, M., Radscheit, M. & W. Barthlott (2007): The cultivation of Titan Arum (Amorphophallus titanum) – A flagship species for Botanic Gardens. Sibbaldia 5: 69-86.
Download a ZIP-file (323 KB) containing information on cultivating the titan arum here.
Korotkova, N. & W. Barthlott (2009): On the thermogenesis of the Titan arum (Amorphophallus titanum) Plant Signaling & Behavior 4:11, 1-3.
Barthlott, W., Szarzynski, J., Vlek, P., Lobin, W., & Korotkova, N. (2008): A torch in the rainforest: thermogenesis of the Titan Arum (Amorphophallus titanum). Plant Biol., doi: 10.1111/j.1438-8677.2008.00147.x
- Amorphophallus titanum
- Picture gallery: Inflorescences 1937-2006 in Bonn
- The Titan Arum in Bonn 1996
- The Titan Arum in Bonn 2000
- Picture gallery 2000
- The Titan Arum in Bonn 2003
- Picture Gallery 2003
- The Titan Arum in Bonn 2006
- Picture Gallery 2006
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