Flowering six feet tall and stinking to high heaven, the surreally magnificent Titan arum plant provided a rare show last summer at its home at the Atlanta Botanical Garden: It bloomed.
The event sent attendance records soaring at the garden–151 percent above average (7,025 visitors during a ten-day period in 1998 compared to 3,708 in 1997)–all attributed to the blooming of this rare Sumatran beauty.
Titan arum is a huge bell-and-clapper inflorescence, or flower cluster. Before last summer’s performance in Atlanta, the species had bloomed only six times in the United States; it is found naturally only on the island of Sumatra in Indonesia, where people call it bangua bangui, or “corpse flower.” It’s related to some medicinal flowers–sweet flag (Acorus calamus), to name one–but is not medicinal itself. Its scientific name is Amorphophallus titanum, which inspires its fair share of Viagra jokes and risqué allusions, but, truly, this plant is remarkable in many ways.
When not in bloom, the plant grows one massive leaf measuring more than ten feet tall and eight to twelve feet around; its stalk looks like the trunk of a small tree. When the change from vegetable to reproductive growth occurs (that is, when the plant moves from leaf to flower), the tip of an enormous gray-green bud emerges from the soil. Here in Atlanta, the plant lives in a massive pot, and the bud looks like a gray “conehead.”
The flower’s progress is amazingly fast, growing about four inches every twenty-four hours and changing noticeably from day to day. As the plant grows, its bud parts to reveal voluptuous pleats of chartreuse petals folded inside (technically referred to as the spathe). As the spadix, or floral spike, elongates, the flower unfolds and gradually turns color. The final opening of the spathe is rapid; it took two hours for the full bloom to show on the Atlanta plant.
The plant is spectacular: An enormous gray-red spadix stretches six feet, two inches above the ruffled burgundy spathe, itself nearly four feet across and chartreuse on the outside. Circling the base of the spadix and hidden deep inside the spathe are the true flowers–between 3,000 and 4,000 of them–all bearing pollen. In a second ring sit more than 700 pistillate flowers with ovaries.
The Titan arum has flowered very rarely in cultivation because it is a heavy feeder, subject to rotting, and extremely difficult to bring into flower. At the Atlanta Botanical Garden, horticulturists housed the Titan arum in the tropical rain forest environment of the Fugua Conservatory. To bring it to bloom, they fertilized the plant for four years with a regimen of cow and chicken manure, bone meal, and liquid 20-20-20.
Beyond its striking looks, the Titan arum’s most memorable characteristic may be its foul odor, which is reminiscent of rancid meat. The odor flows out in waves after the flower fully opens. The smell is used in nature to attract insect pollinators: tiny sweat bees and carrion beetles that typically feed on rotting flesh and lay their eggs in decaying animal carcasses. The odor is a result of thermogenesis, or heating, of the spadix due to chemical reactions inside the plant. The increase in temperature volatilizes plant chemicals, which result in the release of the odor.
All in all, the blooming of the A. titanum was an amazing horticultural event, but perhaps not the last news from Atlanta. Several other tubers may flower within the next year.
Geraldine Laufer is public relations manager for the Atlanta Botanical Garden and a columnist for The Herb Companion, the sister publication of Herbs for Health.