The titan arum blooms in Basel, greenhouse open until two

The Botanical Garden of the University of Basel has announced that its titan arum will bloom tonight. The tropical greenhouse will stay open to the public until two in the morning, with free admission.

Amorphophallus titanum produces the largest inflorescence in the plant world. It can exceed three metres in height and stays open for only three or four days before collapsing. It is this combination of size and brevity that turns each flowering into an event announced days in advance by the botanical gardens that hold a specimen.

The wait in Basel was long. The plant last flowered in July 2023. Between one flowering and the next the specimen accumulates reserves in an underground tuber that can weigh tens of kilos, and it opens its flower only when those reserves suffice.

The species' other well-known feature is its smell. In the early evening hours the inflorescence gives off a particularly unpleasant odour, close to that of decomposing meat. This is not a side effect but the plant's reproductive strategy: the smell attracts carrion-feeding flies and beetles, and it is these insects that carry the pollen. Anyone entering the greenhouse during the night therefore finds the specimen at its point of maximum olfactory intensity, which coincides with its maximum botanical interest.

For those who prefer to avoid the direct experience, the Botanical Garden is streaming the flower's development via a webcam on its website.

The species originates in the rainforests of Sumatra, in Indonesia, and is listed as at risk of extinction. Habitat loss in its native range has made botanical garden collections part of conservation work, and not only a public attraction: specimens grown in Europe and North America make it possible to study the reproductive cycle and to exchange pollen between distant institutions.

Flowerings in Switzerland remain rare. Every announcement produces queues at the entrance and extended opening hours, as in Basel tonight.