Warsaw/ The world's smelliest flower has bloomed for the second time in the botanical garden

The smelliest flower, the giant arum, bloomed for the second time in Warsaw's botanical garden. Throughout the night, internet users followed its progress via online broadcast.

The leaf of the giant arum lily began to open around 9 p.m. on Monday, the University of Warsaw Botanical Garden reported. After 1:30 a.m. on Tuesday, the leaf of the flower, housed in the university greenhouses, opened magnificently.

According to the Garden, the plant needed about 8 hours from inception to full bloom during its previous flowering period in 2021—which would currently be around 5:00 a.m. Back then, the spatha, or leaf, was open for 4-6 hours, the Garden recalled in a Facebook post. Botanists noted that the plant is now older, stronger, and much larger, so it's unclear how quickly it will bloom.

The garden reminded visitors that the greenhouse with the arum will be open to the public on Tuesday from 10:00 a.m. The live broadcast is ongoing on its YouTube channel.

The giant arum lily ( Amorphophallus titanum ) belongs to the Araceae family and is native to the equatorial forests of Sumatra. It produces an inflorescence that can reach three meters in height and over 1.5 meters in width. The inflorescence and leaf arise from a hidden underground tuber weighing up to several dozen kilograms. The inflorescence is open for only two days, so its fragrance spreads over long distances to attract as many pollinators as possible.

In Warsaw, the arum lily is cultivated in the greenhouses of the University of Warsaw Botanical Garden. It bloomed for the first time in June 2021, generating great interest.

Now the arum lily is blooming for the second time, and as an older plant, its inflorescence is much larger than before, having already reached over 180 cm. The inflorescence in 2021 measured 125 centimeters.

"The inflorescence contains female flowers (pistils in the lower part) and male flowers (stamens in the band above the pistils). There are a lot of them, over 400 in total. The female flowers open before the male flowers to prevent self-pollination," said Piotr Dobrzyński, MSc., who cares for the plant.

He explained that a characteristic feature of this plant is that its inflorescence emits a rather distinctive scent, the intensity of which varies daily. It gradually increases from late evening to midnight, when its pollinators, such as carrion beetles and flies, reach their peak activity, and then subsides.

Additionally, the plant heats its inflorescence. This fascinating biological phenomenon is known as thermogenesis. This unusual mechanism plays a key role in the plant's pollination. The heating intensifies the scent and thus attracts pollinators.

During the first phase of flowering, which occurs at night, female flowers are ready for pollination. In the second phase, which occurs on the second day, male flowers release pollen, although the female flowers are no longer receptive to pollination.

– This carefully planned arrangement helps ensure cross-pollination, meaning that fertilization will only be possible between different plant individuals, thus preventing self-pollination – said Dobrzyński.

He noted that if pollination does not occur, the inflorescence dies completely and falls off the tuber.

"If pollination occurs, fruits develop, which turn bright red when ripe. Each individual fruit contains a single seed. The infructescence takes on a shape similar to a corn cob," he added.

Currently, several arum lilies are blooming simultaneously in Europe. (PAP)

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