Massive "Corpse Flower" Set for Rare Blooming in U.S.

by Andrew Jones
National Geographic News

June 5, 2001

Scientists and other observers have been anxiously waiting for the world's largest and smelliest flower to bloom at a greenhouse in the United States. The flower rarely blooms in cultivation.

The plant, known as Titan arum, or "corpse flower," was being closely monitored by botanists and horticulturists at the University of Wisconsin-Madison Botany Greenhouse.

The flowering stalk, which can grow as high as 10 feet (3 meters), produces a bloom that opens to a diameter of 3 to 4 feet (1-1.2 meters). The plant was expected to bloom within a few days—only the twelfth time the blooming of such a flower in the United States has been recorded. The open flower usually lasts approximately 48 hours.

"It's very exciting. We've babied it for a long time," Mohammad Fayyaz, director of the Botany Greenhouse, told the BBC News. "I'm fascinated by this beast. It's a wonderful gift from the plant kingdom."

Best known for its strong putrid smell, Titan arum emits an odor that has been compared with the smell of rotting flesh and can be detected from half a mile away.

The odor, which is usually strongest at night, is meant to attract pollinators such as carrion beetles and flesh flies that are found in the plant's native Sumatra, a major island of Indonesia.

Mary Bauschelt, a horticulturist at the University of Wisconsin-Madison Botany Greenhouse, said a bud first emerged on the plant on April 27, but the staff did not know until almost a month later that it was a flower bud because it was covered in bracts (modified leaves that surround the flower bud to form a protective sheath).

The flower has grown more than five feet since May 21, but recently its growth began to slow.

"It is very hard to determine when the flower will bloom," said Bauschelt. "We know that whenever growth slows, the flower is nearing bloom. Growth has been at 6 inches (15 centimeters) [a day] for a few days, but it is now at 2 inches (5 centimeters). Eventually, growth will actually cease and [the flower] will open."

Titan arum, or Amorphophallus titanum, bloomed for the first time in the United States at the New York Botanical Gardens in 1937. A more recent blooming occurred at the Huntington Botanical Gardens in San Marino, California, in August 1999, when 76,000 people braved the stench to see the flower during the 19 days it was on public display.

Titan arum grows from a large underground tuber that can weigh more than 170 pounds (77 kilograms). Every year the plant produces one leaf stock, or petiole, which has a leaf blade at the top. The leaf dies after one season and an even larger leaf emerges in the next season.

The greenhouse at the University of Wisconsin-Madison recently received donor pollen from a Titan arum plant at the Marie Selby Botanical Gardens in Sarasota, Florida.

"We are using this donor pollen to cross-pollinate our plant," said Bauschelt. "Cross-pollination insures genetic variability."

The Titum arum plant in Wisconsin grew from seeds collected in Sumatra in 1993 in conjunction with the BBC series "Private Life of Plants." The seeds were distributed to a number of U.S. botanists and grew into many of the specimens of the plant that have bloomed in the United States in recent years.