titan arum – Page 5 – My Chicago Botanic Garden

About That Smell…

The night Spike blooms will thrill us all in the semi-tropical greenhouse, with its breathtaking flower…accompanied by a titanically rotten smell.

“Your heart is full of unwashed socks, your soul is full of gunk, Mr. Grinch. The three words that best describe you are as follows— and I quote: stink, stank, stunk!”
—Dr. Seuss

“Titan Tim” Pollak here once again, with an update on Spike, our still-growing titan arum. Spike continues to get bigger, not only in height, but also in girth! What we’re really curious about, however, is the aroma.

The stench is one of the cool reasons to stay up late and come to the Garden that night—we’ll be open from 9 p.m. to 2 a.m.

Here’s what to expect in terms of scent:

What an "arum-atic" combination of scents! — What an “arum-atic” combination of scents!

As the spathe gradually unfurls, the spadix releases powerful odors meant to attract pollinators. The potency of the aroma gradually increases from late evening until the middle of the night and then tapers off as morning arrives.
Analyses of chemicals released by the spadix show the “stench” includes dimethyl trisulfide (like limburger cheese), dimethyl disulfide, trimethylamine (rotting fish), isovaleric acid (sweaty socks), benzyl alcohol (sweet floral scent), phenol (like Chloraseptic), and indole (like mothballs).
The titan arum’s odor has been described in many other terms as well: rotting flesh, rancid meat, rotting animal carcass, old dirty socks, and even the smell of death itself, which accounts for the plant’s common name, the corpse flower.
In its natural habitat on the island of Sumatra in Indonesia, the “fragrance” is used to attract the carrion-eating beetles, dung beetles, and flesh flies that pollinate the titan arum. The inflorescence’s deep red color and texture contribute to the illusion that the spathe is a piece of meat.
During bloom, the tip of the spadix is approximately human body temperature, which helps the fragrance volatilize (turn to vapor) and travel long distances; the heat may also advertise that there’s a fresh carcass for insects to check out.

PHOTO: Dung beetle (Catharsius sp.) — Carrion flies and dung beetles like this one (*Catharsius* sp.) think that stink smells great. Photo ©2012 via potokito-myshot.blogspot.com

A different view of ewwww!

Carrion beetles, dung flies, and flesh flies aren’t responding to the call of the titan arum’s scent because they want to be pollinators—they’re responding because they want a good environment in which to lay their eggs.

In the wild, mama beetles and flies lay eggs on dead animals or animal feces knowing that the larvae that hatch will have an immediately-available, rich source of food.

In its natural rainforest habitat, the titan arum has adapted to that fact. Over evolutionary time, it has developed the right scent to attract those insects—and, like many scented flowers, to deceive them with scent into acting as the unwitting spreaders of their pollen.

Keep checking back for more on Spike’s progress!

Spike’s Wild World

“Where does a titan arum come from?” That’s a question we heard a lot from Spike’s visitors this past weekend.

MAP: Sumatra, highlighting the western mountain range of the island. — Titan arum occurs throughout the Barisan mountain range in West Sumatra, Indonesia.

The titan arum, native to the rainforests of the island of Sumatra in Indonesia, was first “discovered” by Italian botanist Odoardo Beccari in 1878. On August 6, 1878, he first observed the leaves and fruits of a plant (interestingly, August 6 is the date we put Spike on public view!). Several weeks later, Beccari saw a flowering plant for the first time. He sent a few tubers and seeds to Florence, Italy, but the tubers all perished; a few seeds, however, eventually germinated. One of those seedlings was sent to the Royal Botanic Gardens, Kew, in England. There, in 1889, 11 years after its discovery, a titan arum plant flowered for the first time outside its tropical home.

No one knows how common the titan arum is in the wild. Many suspect it is endangered. Its only known habitat is the rainforest of Sumatra, which is being steadily eroded by deforestation for palm oil production, by pollution, and by human encroachment. The corms are also being dug up for food—and by collectors or poachers.

PHOTO: Kerinci Seblat National Park, Sumatra, Indonesia. Photo by Luke Mackin. — Kerinci Seblat National Park in Sumatra, Indonesia, features dense rainforest. Photo by Luke Mackin

Also contributing to their demise is the fact that many species in the genus Amorphophallus, including the titan arum, are highly endemic. This means that they are only found in relatively small, restricted geographical areas. If the rainforest home of these species is destroyed, we will continue to see their numbers decrease.

PHOTO: Titan arum (Amorphophallus titanum) in bloom in its native habitat in Sumatra. Photo © Luke Mackin/Wild Sumatra — Finding a titan arum (*Amorphophallus titanum*) in bloom in its native habitat is a thrilling experience. Photo © Luke Mackin

What can we do to help conserve the titan arum and similar plants? Start by learning more about tropical rainforests, and the impact of deforestation in these areas. Support your local botanic gardens, arboreta, and universities where scientists are studying endangered plant species and promoting the importance of plant conservation.

The titan arum (Amorphophallus titanum) is one of the plant kingdom’s most spectacular phenomena—and spectacular plants help us all to realize the incredible complexity and diversity of the natural world.

Become a Garden member and support the world’s spectacular plants, like Spike, at the Chicago Botanic Garden: We cultivate the power of plants to sustain and enrich life.

We are getting closer to bloom time! Check our website, and #CBGSpike on social media to stay on top of bloom updates!

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.

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.
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.
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.
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!
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…

Is Spike Blooming Yet?

Spike is about halfway up the expected height chart (we’re thinking 6 to 7 feet, ultimately), so the big question now is, “How do you know when it’s going to bloom?”

PHOTO: Taken yesterday (August 11, 2015), our titan arum reaches the "halfway" point in its growth chart. — Taken yesterday (August 11, 2015), our titan arum reaches the “halfway” point in its growth chart.

Titan arums don’t give up their secrets easily. Just as it’s difficult to distinguish a leaf bud from a flower bud (we talked about that in our last blog post), it’s hard to know when the bloom cycle has actually begun.

Once again, our titan-experienced friends at other botanic gardens and conservatories have offered up a few helpful hints.

PHOTO: Closeup of spathe loosening from spadix of Amorphophallus titanum at the Sydney Royal Botanic Gardens 2 days before opening (in 2008). — A close-up shows the spathe loosening from spadix of *Amorphophallus titanum* at the Sydney Royal Botanic Garden two days before opening (in 2008).

Growth slows. Spike is powering up 4 to 6 inches per day. As a titan gets ready to open, that growth rate slows noticeably. It’s a rather obvious clue, but by the time the plant is 6 or 7 feet tall, you start to marvel at the overall size and forget about incremental daily growth. We’re posting our measurements daily here, so heads up when you notice the numbers getting smaller.
Bracts fall. What? Look down at the base of the spathe. Two modified leaves called bracts encircle the spathe. As Spike gets taller, these protective bracts shrivel and dry up. About a day before full bloom, they fall off—first one, then the other. That’s a sure sign that bloom is about to happen.
The spathe loosens. Tightly wound around the towering spadix as it shoots up, the frilly leaf called a spathe starts to loosen its grip as bloom time nears, revealing the crazy-beautiful maroon color inside.

So those are the clues we’re watching for—now you can watch for them, too! How long will it be before the big night? I’ll keep you posted…

Prepare for “Wow!”

Yesterday we moved our first titan arum (Amorphophallus titanum), “Spike,” to the Semitropical Greenhouse. Now we are all watching and waiting for Spike to bloom—a dream of the Chicago Botanic Garden for 12 years! Finally, in the next ten days or so, we’ll see the fruit of our labor in all of its stinky glory.

PHOTO: Meet Spike, our titan arum (Amorphophallus titanum). — Meet Spike, our titan arum (*Amorphophallus titanum*). We expect great things from this magnificent plant.

What’s next, and when?

Over the next several days, Spike will grow taller—some days, a barely noticeable inch, and other days, a remarkable 4 or 5 inches. Below the soil is a giant corm, which is a type of underground tuber or bulb (some can weight up to 200 pounds). The titan arum bloom has previously gone through three to ten annual cycles of emerging as a leafy stalk, dying back, and sending that energy back into the corm, which began as a germinated seed about the size of a quarter.

Big bloom!

While it will look like Spike is a 6- to 8-foot-tall flower, what you will see is actually a tall spadix (flower structure) wrapped by a spathe (a frilly modified leaf). Over the next week, the spadix will emerge out of the top of the bud and continue to grow taller, until it’s time for the bloom. For a single day, the spathe will unwrap and open to a dark, velvety red “bloom,” closing again roughly 24 hours later.

Big stench. No, really.

Inside the tightly wrapped spathe, the plant uses stored energy from the corm to heat up internally to 90+ degrees Fahrenheit. As the spathe opens, the 750 small female flowers ringing the bottom of the spadix release scent molecules that are volatilized (vaporized) by the heat, creating a blast of scent so powerful that it can travel an acre (or the distance between individual plants in their native Sumatran rain forests). The scent is a calling card for pollinators.

PHOTO: The spathe of the Amorphophallus titanum unwraps from the spadix at bloom time. — The spathe unwraps from the spadix at bloom time. Photo by Elke Wetzig (elya) (Own work) [GFDL, CC-BY-SA-3.0 or CC BY-SA 2.5-2.0-1.0], via Wikimedia Commons

What does Spike smell like? Chemically, the scent is a combination of dimethyl trisulfide, isovaleric acid, dimethyl disulfide, and trimethylamine—or, as our friends at Huntington Botanic Gardens described it, “a combination of limburger cheese, garlic, rotting fish, and smelly feet.”

The titan arum will be worth the wait! (Follow our #CBGSpike)

This is yet another “Wow!” produced by our production greenhouse staff for our visitors to rave about.

Other Chicago Botanic Garden “Wows”:

More than 180,000 colorful and bountiful annuals and vegetables produced for displays throughout the Garden
The stunning and dramatic cascading chrysanthemums seen atop the bridge at the Visitor Center each fall, and the nearly 100 or so chrysanthemum “balls” we create every year for display in the Esplanade
The 10-foot-tall floral pyramids and blooming obelisks created to enhance seasonal displays

But Spike is the most distinguished of them all.

When Spike is ready to bloom, the Chicago Botanic Garden will stay open until 2 a.m., so everyone will have a chance to take in the odor and the remarkable color of the world’s largest unbranched inflorescence—a “Wow!” indeed.