Titan Arum

The titan arum belongs to the arum family and the genus Amorphophallus, which comprises over 200 species. The species Amorphophallus titanum is endemic to the Indonesian island of Sumatra, where it grows in tropical rainforests.

The plant develops an underground tuber that can weigh over 110 kilograms. From this tuber, the titan arum alternately produces either a single leaf or a flower spike. During the leaf phase, the plant performs photosynthesis and stores the nutrients it produces in the tuber. The leaf can grow up to six meters tall and resembles a small tree in shape, as it is divided into several parts at the top. 

Particularly remarkable is the inflorescence, which makes the titan arum a botanical rarity: It appears only about once every three years and remains open for just three days. At over three meters tall, it is considered the largest unbranched inflorescence in the world. During the blooming period, the plant emits an intense odor strongly reminiscent of carrion. This odor, which is extremely unpleasant to humans, serves to attract pollinating insects. 
The inflorescence consists of numerous individual flowers located at the lower end of the spadix. The flowers are surrounded by a spathe, which opens during the flowering period. The flowers are divided into female flowers, which are located at the very bottom, and male flowers, which are situated slightly higher up. Pollination is carried out by insects that travel from the upper section with the male flowers down to the female flowers, transferring pollen in the process. 

Wild populations of the titan arum on Sumatra are in sharp decline. Today, only a few hundred specimens remain, representing a decline of about 50% over the last century. The main causes of this decline are the loss of their natural habitat and the harvesting of the plants by humans. The titan arum is now cultivated in more than 90 botanical gardens worldwide. Through their care and propagation, these gardens—as well as the Zurich Zoo—are contributing to the conservation of this extraordinary plant species.