Amorphophallus titanum

The Titan Arum in Bonn 2006

Flowering titan arums in Bonn are almost traditional by now - the event in May 2006 marks the ninth and tenth time, after 1937, 1940, 1987, 1996 (two plants), 1998, 2000 and 2003, that we are having titan arums flowering here. This is also why we have chosen the titan arum as the symbol for our garden.

The 1997 inflorescence was used for numerous scientific studies, the results of which were published by Barthlott & Lobin in 1998.

The largest titan arum inflorescences

  • 1. Bonn (Germany), May 2003, 274 cm
  • 2. Wageningen (The Netherlands), 1932, 267 cm
  • 3. Bogor (Indonesia), 261 cm
  • 4. Bonn (Germany), 2000, 257,5 cm
  • 5. New York (USA), 1937, 256,5 cm
  • * Frankfurt (Germany), 1985, circa 250 cm
    (* In contrast to the other flowerings, the Frankfurt plant was measured from the tuber upward (2.7m). For comparison with other plants, therefore, about 20 cm have to be deducted.)

We received our largest and oldest plant from Professor Kohlenbach, University of Frankfurt, on 8th June 1988. On 6th July 2000, the plant flowered for the first time. Its inflorescence reached a height of 257.5 cm (287.5 cm from the tuber). Our 2003 inflorescence was entered into the Guinness Book of Records. In 2005, a Titan Arum flowered at the Wilhelma in Stuttgart; at 294 cm (measured from the soil surface), its inflorescence reached the greatest height measured to date.

When the inflorescence rotted away, a new leaf had already formed on 22nd October 2003, which retracted on 10th January 2005, that is, after 14 months. On 21st March 2005, the tuber was taken out of its pot and weighed; it came to a stunning 117 kg. On 22nd March 2005, it was repotted, and it was only 12 months later, on 9th April 2006, that the first shoot reached the soil surface. To our surprise, on 9th April 2006, a second bud came through, and on 22nd April 2006, it was followed by No.3.

Diagrams: Growth rates and height gain

Daily growth rates in cm
Daily height gain in cm

Height gain on 4th and 5th May 2006

Height gain on 4th and 5th May 2006

On May 4th and 5th, Arne Erpenbach and members of the garden staff measured the height gain of the plant continuously every two hours, during the night as well as during the day. As in a previous measurement, growth was seen to be almost linear at 2 cm per 2 hours.

The first two buds have now revealed themselves to be flower buds. So far only once has there been more than one bud on a plant, and all of these buds turned into leaves. This makes our plant the first one in the world to have more than one inflorescence at a time.

On 29th April 2006, the appendix of the first bud started to show, and on 1st May 2006, that of the second one. Meanwhile, the third bud has also revealed itself to be a flower bud.

Inflorescences in Bonn
Date Weight Height
21st April 1937 22,5 kg 181 cm
July 1940 / /
8th April 1987 / 161 cm
8th May 1996 32 kg 233 cm
30th May 1996 50 kg 169 cm
30th April 1998 27 kg 172 cm
7th July 2000 36 kg 257,5 cm
22nd May 2003 78 kg 274 cm
May 2006 117 kg 259/225,5/165,5 cm


  1. Amorphophallus titanum
  2. Picture gallery: Inflorescences 1937-2006 in Bonn
  3. The Titan Arum in Bonn 1996
  4. The Titan Arum in Bonn 2000
  5. Picture gallery 2000
  6. The Titan Arum in Bonn 2003
  7. Picture Gallery 2003
  8. The Titan Arum in Bonn 2006
  9. Picture Gallery 2006
  10. Literature & Links
  11. Guinness-Certificate