Family: Araceae
Scientific name: Amorphophallus titanum
Common name: Titan arum
Origin: West-Sumatra (Indonesia)

This rare and exceptional species produces the largest unbranched inflorescence in the world. The gigantic inflorescence is surrounded by a purple-green bract and can get 3 metres tall! The inflorescence contains hundreds of male and female flowers that don’t open at the same time to prevent self-pollination. First the female flowers are fertile and 1-2 days later the male flowers start giving off pollen. The whole inflorescence dies off after 2-4 days already, because it costs the plant an immense amount of energy. This energy cost is due to the size of the flower off course, but also due to a chemical process to keep the flower at a constant temperature of 37 degrees Celsius. Because of this heat the pungent carrion scent can spread better, and the flowers also become more attractive to flies and beetles that pollinate them. They are fooled by the plant in thinking they are visiting a fresh animal carcass to lay eggs, which is strengthened further by the purple colour of the bracts that imitates the colour of red meat.

The species originates from the Barisan mountains in the west of Sumatra, where it grows in open spaces on the hills of the rainforest and can flower 1 to 3 times a year. In Europe the species can be fount in botanical gardens where it flowers less often. The species is actually quite easy to keep as a houseplant, where the elegant leaves take the main stage. The parasol-shaped leaf has a spotted stem and there is always only 1 leaf at a time. Every time a leaf dies a new one comes up that is a bit larger, which can even get 5 metres tall in tropical conditions. On average the plant goes into a rest state once a year, which means there will be nothing visible above ground and only the underground tuber remains. When the tuber has reaches a weight of 50kg, within 8-10 years, the plant has enough resources to be able to flower. However, the temperature will also have to be around 25-30 degrees Celsius for it to flower, so in reality it can only flower in a heated glasshouse. That might also be a better place for a plant like this to flower instead of a living room considering the size and horrid smell…. Make sure to provide a well-draining soil, like a mix of potting soil, tree-bark, orchid soil, and/or sphagnum moss. The soil should be kept lightly moist, including during the period of rest. Furthermore it is a good idea to regularly spray the leaf with water, especially if the humidity is below 75%. You can also give liquid fertiliser during the growth phase and provide new soil during the rest period.

Sowing description: The seed has a short shelf life and can be sown directly in Sphagnum moss (usually available at gardening centres). Cover the container/greenhouse/bag with plastic or glass (to keep it moist). Germination usually occurs within a few weeks at 25-30 degrees Celsius. If the seed has germinated, u can transfer it to the mix described in the species description: a combination of potting soil, tree-bark, orchid soil and/or Sphagnum moss.

Sowing time: Whole year
Difficulty: Intermediate 
Minimum temperature: 15 degrees Celsius