The phallus-shaped bloom of the titan arum, a flower native to the western Sumatra equatorial rainforest in Indonesia, reached a height of 255 centimetres, a new record, the botanical garden said.
In previous years the bloom of the largest flower in the plant kingdom reached 230cm (2012) and 193cm (in 2011, when it flowered for the first time).
Its size this year falls just short of the world record for tallest titan arum bloom in cultivation of 274 cm set in 2003 by the botanical garden at the University of Bonn in Germany.
In the wild it can grow to three metres high.
The University of Basel’s plant is located in a greenhouse that is open to the public on Monday until 11pm.
The brief bloom is followed by a “stench” phase when the plant releases powerful odours designed to attract pollinators such as beetles.
Because of these smells, described variously as being similar to rotting fish, sweaty socks, mothballs and limberger cheese, the plant is also sometimes known as the corpse flower.
It blooms irregularly sometimes at intervals as long as two to 10 years.
The botanical garden first germinated its titan arum in 1993 from a fruit taken from a mother plant in Frankfurt.
It normally takes seven to 10 years of growth before the first bloom occurs.
The botanical garden said it was conducting a pollination experiment on the plant using frozen pollen from another titan arum plant from the botanical garden in Beirut.
Special opening times for the rest of the week will be announced on the garden’s website.
The fee for visits is five francs with free admission for children 12 and under.
More information is available (in German) from the botanical garden's website.