Stinking beauty: Rare flower set to bloom at UW-Madison

One of the world’s largest and most malodorous flowers is about to bloom on campus.

The titan arum or “corpse flower,” noted for a malodorous stench given off by blooms that can have a diameter of as much as four feet, is exceedingly rare among cultivated plants. The nascent bloom at UW–Madison is the first in Wisconsin and may be only the twelfth recorded bloom in the United States.

“It’s very exciting. We’ve babied it for a long time,” says Mohammad Fayyaz, director of the Botany Greenhouses and Garden of the College of Letters and Science, where the plant has been in residence for the past seven years. “I’m fascinated by this beast. It’s a wonderful gift from the plant kingdom.”

Native to the equatorial rain forests of Sumatra in Indonesia, titan arum first blossomed under cultivation in England in 1889. Specimens have flowered several times in captivity since at Kew Gardens in England, the United States and elsewhere, each time causing a sensation and attracting thousands of curious people. The excitement at Kew when the titan flowered a second time was so great that police had to be called to control the crowd.

The plant grows from a tuber that can weigh as much as 170 pounds. When in flower, it gives off a stench that serves to attract pollinators which, in its Sumatran home, are thought to be carrion and dung beetles, and sweat bees.

The corpse flower blossom lasts only a few days before collapsing under its own weight. The “flower” is actually a leafy structure called a spathe.

Within, at the base of a fleshy central column called the spadix, are thousands of tiny male and female flowers. Only when the spathe is completely unfurled are the flowers mature.

Strictly speaking, it isn’t a “true” flower at all, but an “inflorescence,” or collection of flowers, which emerges at the end of a long dormant period, growing up to 4 inches a day over a period of about three weeks. As the pale yellow spike reaches maturity, the spathe opens out to form a vast, ribbed, frilly-edged trumpet, greenish on the outside but deep maroon within.

The plant, whose scientific name is Amorphophallus titanum, is a member of the same family that includes calla lilies and philodendrons. It may bloom only two or three times during a 40-year life span. In the forests of Sumatra, the single umbrella-type leaf can reach 15 feet across, on top of a 20-foot stem, while the underground tuber from which first the leaf, and later the flower, emerges, can be so heavy that it requires two people to pick it up. Sumatran legend has it that the plant will even eat its grower, hence the local name of “corpse flower.”

But one of the plant’s most unusual features, in addition to its size, is the extraordinary smell: At the moment when the titan arum’s pollen is receptive, the spadix actually heats up from within and gives off a powerfully malodorous stench of rotting fish — perfect for attracting the carrion beetles and sweat bees that pollinate it.

As of Friday, May 25, the UW–Madison plant was four feet tall and growing at a rate of about four inches a day, says Fayyaz. The flower is expected to open any time within the next week or two.