The Amorphophallus Konjac - better known as the Voodoo Lily - gives off a smell similar to rotting meat to attract flies to pollenate it.
Staff at the National Botanic Garden of Wales, in Carmarthenshire, hope the plant's strong aroma will entice curious visitors rather than putting them off.
A spokesman for the garden said: 'Hopefully, people will come along and give it a whiff. It's one of nature's gifts.
Our gardener in charge of the tropical house says it will be stinking the house out by the end of the day and we're hoping the smell will last until the weekend so as many people as possible can experience it.'
The three-and-a-half foot high plant goes by many names, including Devil's Tongue and Elephant Yam, although Voodoo Lily is the most popular.
A native to warm subtropical to tropical eastern Asia, the plant was given a home in the garden just under a year ago.
