GIF: The titan arum nears 3 feet in height today!

A Titan Leaf or a Titan Bloom?

“Titan Tim” Pollak here, with today’s update on Spike, our first-ever corpse flower.

PHOTO: The corm of an Amorphophallus titanum: after a dozen or so years, it's large enough to produce a bloom!
The corm of an Amorphophallus titanum: after a dozen or so years, it’s large enough to produce a bloom!

Spike just keeps on growing at the Semitropical Greenhouse, and visitors are loving it. As they learn more about the coming bloom from the docents posted there, one of the most frequently ask questions is, “How could you tell this time that Spike was a flower?”

How could we tell that Spike was going to be a flower? It’s tricky. Even the most experienced botanists have a hard time determining whether a titan arum shoot is a flower or a leaf at first. But soon enough, the clues start to add up.

PHOTO: An Amorphophallus titanum shoot to the right of a leaf stalk provides comparison for determining the slight bulge which could mean a flower bud.
An Amorphophallus titanum shoot to the right of a leaf stalk provides comparison for determining the slight bulge, which could mean a flower bud.
PHOTO: The emerging Amorphophallus titanum plant looks leafy, unlike the smooth spadix which emerges from a flower bud.
The emerging Amorphophallus titanum plant looks leafy, unlike the smooth spadix that emerges from a flower bud.
  1. Spike is 12 years old. We know from other botanic gardens and conservatories that titan arums take a decade or more to send up their first flower shoot. We’ve been tending to this corm for about 12 years, so the timing was right.
  2. Is the corm big enough? The smaller the corm, the less power it has stored to send up the titan’s huge flower. This corm is about the size of a beach ball—definitely an appropriate size for flowering.
  3. A bulge at the base. It’s subtle, but a slight swelling at the base of the newly emerged shoot signaled something different than a leaf.
  4. A little off center. At 18 to 20 inches tall, we noticed a telltale sign: the tip of the shoot was off-center. While leaf shoots are true to center, we knew that a flower shoot powers up in a slightly different way. Again: it’s subtle but telling!
  5. Horticultural intuition. Both Deb Moore—our indoor floriculturist who tends to our nine titan arums—and I felt that the overall look of the shoot was different than what we’d experienced before with shoots that become a leaf. (While the titan’s non-bloom form may look like a stalk with multiple leaves, it is actually a single, giant leaf!) Like every gardener, you develop a sense for what’s “normal” and what’s not when it comes to your plants. We both thought that this shoot was somehow different, and it was!
PHOTO: While these may look like branches and leaves, each of these Amorphophallus titanum are actually single-leaf plants.
While these may look like branches and leaves, each of these Amorphophallus titanum are actually single-leaf plants.

Our final “sign” was to ask the experienced titan growers from other institutions. We called upon the folks at the Huntington Library, Art Collections, and Botanical Gardens in San Marino, California; Smithsonian Gardens in Washington, D.C.; Phipps Conservatory and Botanical Gardens in Pittsburgh, Pennsylvania; and Missouri Botanical Garden in St. Louis, Missouri, for their opinions and expertise. Their final confirmations gave us the thumbs up to go public with the big news that Spike would soon blast into bloom!

Like first-time parents, we are learning as we go. I can’t tell you how excited we all are in the production greenhouses—it’s a thrill to watch a plant that you’ve tended for so long finally get ready to flower! Visitors’ anticipation is rubbing off on us, too—we’ll be standing right next to you as the titan arum heads into its big night of bloom!

I’ll keep you posted…


©2015 Chicago Botanic Garden and my.chicagobotanic.org

Published by

Tim Pollak

"Titan" Tim Pollak is outdoor floriculturist for the Chicago Botanic Garden. He earned his BS degree from Colorado State University in Landscape Management and Nursery and Greenhouse Management.

5 thoughts on “A Titan Leaf or a Titan Bloom?”

  1. When the flower blooms, will you move it outside? Will the bugs be swarming the building to get in and pollinate? This is very exciting…sorry if someone asked these questions before first visit here.

  2. Hi Katpie
    No we plan to keep Spike inside the Semi-tropical greenhouse through its bloom and thereafter. We will be trying to pollinate it ourselves with “donor pollen” within 12 hrs after the flower is fully open. Very exciting…..

  3. During the course of the 10-12 years when Spike was not in the blooming cycle, how many times did it go through the “leafing cycle”? As I understand its growth pattern (which is fascinating!!), it leafs out its single leaf, which dies back after awhile. But did Spike leaf out again (or multiple times) until the corm got big enough for the current shoot to emerge? Thanks for updates!!

  4. hi tim just wanted 2 let u know much I love watching and seeing the corpse flowers bloom I wish

    I could be there in person 2 really see and smell them when they bloom?

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