Another corpse flower to bloom

For the second time in a little more than a year, one of the world’s largest and most malodorous flowers will bloom at the university.

The titan arum or “corpse flower,” noted for a nasty stench given off by blooms that can have a diameter of as much as four feet, is exceedingly rare among cultivated plants.

As of this afternoon, Tuesday, July 23, the plant — different from the one that which bloomed on June 7, 2001 — was 49 inches tall and growing several inches a day. The flower is expected to open within the next week or two.

The new nascent bloom at UW–Madison comes on the heels of the bloom that attracted thousands of curious visitors to the small Botany Department greenhouse last summer and crashed the university’s Web server as tens of thousands of plant lovers from around the world tuned in to live Web images of the blossom.

“I couldn’t believe it when I saw it,” says Mohammad Fayyaz, director of the UW–Madison Botany Greenhouses and Garden where the second plant is also in residence. “I talked to it. I said, ‘You’re a leaf. You’re not going to be a flower. You’re a leaf.’ But it’s a flower!” Fayyaz missed last year’s bloom due to a vacation abroad.

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 most recent bloom in the United States occurred just last week at the Quail Botanical Gardens in Encinitas, California.

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 that, in its Sumatran home, are thought to be carrion, dung beetles and sweat bees.

The 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 four 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 and deep maroon within.

The plant, whose scientific name is Amorphophallus titanum, is a member of the family Araceae, which also 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.

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.

The greenhouse, located behind Birge Hall on Lathrop Drive, will be open for public viewing of the titan arum from 10 a.m.-6 p.m. daily starting Monday, July 29. Hours will be extended as the bloom time gets closer.

A live Web cam and Web site also are planned. More information will be available later this week.