How the 'corpse flower' creates its horrible odour - and why it needs it

They bloom only once every seven to 10 years, and the flowering lasts only two nights. During this time, the giant flower, up to three metres high, emits the smell of rotting meat to attract pollinating insects. But what exactly creates this stinking aroma?

Researchers from the University of Colorado, as reported by The Conversation, decided to approach the problem from the perspective of atmospheric chemistry. They analysed the composition of the air around a flower called Cosmo - a rare specimen of Titan arum grown in the laboratory. It turned out that it is the female flowers of the plant that emit the greatest amount of volatile substances, and they do it on the first night of flowering.

The main component is methanethiol, a compound related to those that cause the odour of skunks. Other malodours have also been identified in the composition: dimethyl disulfide (smells like garlic), dimethyl sulfide and dimethyl trisulfide (associated with the smell of cabbage and onions). Together, they create a convincing illusion of decomposing flesh, which flies and beetles flock to, able to transfer the pollen to another plant.

Interestingly, plants use a 'flower trap' strategy: on the first night, when the female flowers bloom, insects are attracted by the odour and are trapped inside the flower chamber. In the morning, evaporation stops abruptly, possibly due to the partial closure of the chamber. On the second night, the male flowers bloom, and the already "captive" insects receive pollen, which they then carry to other flowers.

In addition to the odour, the titanic flower heats itself up to human body temperature - this helps to spread the smell even further into the jungle.

Scientists have calculated that during flowering, the plant loses up to 0.4% of its mass due to the compounds released - that's almost half a kilogram!