University Times

A rare event is in progress in the University’s greenhouse in Langley Hall. An amorphophallus titanum is preparing to bloom for the first time.

In a Feb. 25 photo, above, Tom Harper checks on “Tatiana,” a titan arum that is preparing to bloom for the first time in a Pitt greenhouse. Harper, who manages the Department of Biological Sciences’ microscopy and imaging facility, has been documenting the plant’s rapid progress in photos that will be posted on the greenhouse web page later this month. The plant’s speedy growth is evident in a March 1 photo, below, in which Tatiana has grown more than a foot taller than the thermostat on the greenhouse wall. The plant, native to the Sumatran rain forest, can grow several inches a day as it prepares to bloom, slowing just before its short-lived but foul-smelling flower opens. Greenhouse manager Ellen York expects the huge bloom to open early next week.

Blooming is a big thing for the titan arum. Native to the Sumatran rainforest, the plants bloom just once every three-five years in the wild, and even less frequently in greenhouses.

According to Pitt’s plant growth facilities manager Ellen York, there have been fewer than 200 documented bloomings under glass since the titan arum was discovered in the late 1800s.

And when the titan arum does flower, its bloom is … well, titanic.

While another Indonesian plant, rafflesia arnoldii, has the distinction as the world’s largest flower, the titan arum is the plant with the world’s largest inflorescence, or cluster of flowers. Its bloom consists of a maroon and green skirt-like spathe surrounding a tall central spadix, which contains rings of male and female flowers near its base.

One of a pair of titan arums at Pitt, the budding Tatiana (named for the patron saint of students, as well as for the taxonomic alliteration) could reach 7 feet tall in full bloom.

York received the titan arums — offspring of the University of Wisconsin-Madison’s “Big Bucky” — as 5-inch-tall seedlings nearly a decade ago at a national meeting of the Association of Education and Research Greenhouse Curators.

The titan arum’s thick leaf stalks are 5-7 feet tall. While Tatiana’s non-blooming sibling has four umbrella-like leaves, Tatiana, who now is sporting one leaf and one bud, had only one massive leaf about the width of a person’s calf, York said.

Only recently did Tatiana show signs of blooming. The leaf had died back, and early last week York noticed swelling at the base of the plant, which revealed itself to be a bud that by Friday had grown to a height of more than 3 feet.

The plant will grow rapidly, slowing as it approaches full bloom, which lasts only a day or two.

The event is a bit of a mixed blessing. The titan arum’s other nickname is carrion flower. When the bloom opens, it will reek of rotting flesh — the plant’s way of enticing the carrion beetles and flesh flies that pollinate it.

“One big inflorescence every three-five years means the likelihood of synchronizing with another plant in bloom at the same time is rare. They do a lot of work to attract their pollinators,” York added, noting that the titan arum will produce heat, warming itself to approximately human body temperature to help volatilize the sulfur compounds that produce its characteristic and nauseating odor. (Several members of the arum family — including a pungent local relative, the skunk cabbage — have similar thermogenic ability, York noted.)

With no carrion beetles or flesh flies nearby, York said she will collect and freeze some pollen and will attempt to help Tatiana self-pollinate in hopes of producing seeds that can be shared.

While blooming titan arums have drawn crowds at public greenhouses and conservatories, Tatiana’s big day will come in the relative privacy of her hot and humid greenhouse home in Clapp Hall, which is not open to the public.

However, Tom Harper, who manages the Department of Biological Sciences’ microscopy and imaging facility, has been capturing photos of Tatiana’s daily progress. After blooming is complete, York plans to post photos at www.pitt.edu/~biohome/Dept/Frame/greenhouses.htm.

Information on titan arums, including documentation of Big Bucky’s blooming, can be found at www.news.wisc.edu/titanarum.

—Kimberly K. Barlow