Rare, pungent flower to get some cross-country love

In true rain forest fashion, Amorphophallus titanum prefers the company of pollinating carrion beetles.

In a greenhouse in Madison, Wis., the rare, large and very malodorous flower will have to settle for university botanist Paul Berry. Berry has the improbable task of aiding the fertilization of a plant commonly known as the “corpse flower,” or titan arum, a plant native to the jungles of Sumatra that blooms so infrequently that fewer than 15 blooms have been recorded in cultivated plants in the United States over the past 60 years.

Berry, in fact, will be using donor pollen from a second titan arum that just finished flowering at Selby Botanical Gardens in Sarasota, Fla.

“We plan to pollinate the plant when the female flowers are receptive,” says Berry. “Since pollen from our plant will only be shed once the female flowers have finished flowering, we need to have pollen on hand from an earlier blooming plant to place on the female flowers as soon as they open.”

The titan arum “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.

In its native equatorial rain forest, the titan arum depends on carrion beetles and sweat bees to carry pollen from one plant to another. The plant’s notorious odor, described as a cross between rotting flesh and burnt sugar, helps attract the insects that it depends on for reproduction.

To artificially pollinate the tiny flowers within, Berry will cut a small window in the back of the spathe and use cotton swabs coated with the pollen from the Selby Gardens titan arum. The stringy pollen are the male sex cells that form in the stamen, the pollen-bearing organ in a flower. The pollen is applied to the stigmas of the female flowers which, after fertilization, develop into a seed cluster.

The pollen was shipped to Madison Tuesday, June 5, by scientists at Florida’s Selby Botanical Gardens. Selby Gardens bloomed two titan arums within days of each other in 1999 and successfully pollinated the second plant with pollen from the first. The resulting seed was distributed to botanical gardens around the world.

The UW–Madison titan arum is less than eight years old and was grown from seed collected in Sumatra, Indonesia, on the same expedition where David Attenborough filmed the BBC series “The Secret Life of Plants.”

So far, the Wisconsin plant is 98-inches tall, just a few inches shy of the record set by the plant that bloomed from a 100-pound tuber in 1937 at the New York Botanical Garden. It is anticipated that the spathe will begin to unfurl later this week, perhaps Thursday or Friday. Within hours, the female flowers within the spathe will mature and be receptive to pollen.