Jennifer Schultz Nelson
Extension Educator, Horticulture
People are fascinated by some pretty bizarre things. I confirmed what I already knew earlier this month, when I joined the crowds lured to the University of Illinois Plant Biology Conservatory to witness the blooming of their Amorphophallus titanum—theirs is nicknamed "Titania". Why the fascination? Well, one major reason is its common name is Corpse flower, because it smells like rotting meat. It is also the world's largest inflorescence.
The Titan arum is native to the shady rainforests of Sumatra. It was first described by Italian botanist Odoardo Beccari in 1878. He brought seed back to Europe, and the first flowering of this plant while in cultivation was at the Royal Botanic Gardens at Kew in England in 1889.
It took awhile before the United States had a Titan arum bloom of their own. Success came in 1937 at the New York Botanical Garden. The U.S. did not see another Titan arum bloom until 1998, when three plants bloomed that year, one each at the University of Missouri, St. Louis, Fairchild Botanical Gardens, Florida, and Atlanta Botanical Gardens, Georgia. Since 1998, there have been blooms recorded in a wide variety of places throughout the U.S.
There are several reasons, besides its odor, that seeing a Titan arum in bloom is a special event. For one, it is a very difficult plant to grow, and it takes approximately ten years before it blooms for the first time from seed. The Titan arum grows from a large underground corm, which resembles a knobby potato. These have weighed in at up to 200 pounds! The U of I Titan arum weighed in at a petite 38 pounds in comparison. These are very tricky to keep in a greenhouse, as they are very prone to rotting. So it is a feat by itself just to keep them alive year to year.
The corm stores energy that the plant needs to produce one large leaf each year, and once it reaches a large enough size (which means lots of stored energy) it is capable of flowering. Until flowering size is reached, the corm is dormant for several months each year, and only produces a single leaf. That may not sound like much, but that leaf is enormous. It may reach 20 feet tall and 15 feet in circumference. To me it resembles a palm tree—one big green stalk supporting many leaflets. But botanically speaking it is a single leaf. The sugars produced through photosynthesis in this leaf are stored in the corm, helping it to grow larger each year.
When the corm reaches flowering size, then the fun begins. That year, the plant produces a flower before the leaf. Listening to my friends that work in and near the conservatory, discovering that the Titan arum would flower this year was like someone announcing they were pregnant—and waiting for the bloom to open was like waiting for a baby to be born!
The stored energy in the corm produced a very large, nearly 5 foot tall inflorescence that grew incredibly fast, multiple inches per day. Being its first flowering, this inflorescence was on the small side- Titan arum inflorescences have been measured at over ten feet high! There are two parts to the Titan arum inflorescence, the spathe, which resembles a pleated skirt, and the spadix, which is a large fleshy column that turns purple as the inflorescence blooms. Those of you that know Latin will find that the genus name Amorphophallus comes from the description of the spadix. In the interest of keeping this article G-rated, I'll stop there.
The Titan arum is technically the largest inflorescence, because there are actually multiple tiny flowers arranged at the base of the spadix. The title of largest flower belongs to Rafflesia, a genus of parasitic plants that smell just as bad as the Titan arum inflorescence.
During its blooming, the Titan arum releases two very odiferous sulfur containing compounds, which do a great job of mimicking the smell of rotting meat, which attracts various flies and carrion beetles, its preferred pollinators. Somehow, it also attracts people that want to see if the smell is really that bad. I will tell you, that yes, the smell really is that bad. It reminded me of dead fish rotting in the sun on a bed of rotting cabbage.
In the wild, these plants occur fairly far apart from each other. In order to spread their lovely fragrance far and wide and attract lots of pollinators, the spadix portion of the inflorescence heats up to about 100 degrees Fahrenheit. Scientists think that evolving this mechanism of attracting flies and beetles from miles away was one way to ensure cross pollination. The Titan arum cannot typically pollinate itself; it needs pollen from another plant.
Due to the enormous energy demands of producing an inflorescence of this gigantic size, the inflorescence is only open for approximately 48 hours. If it is pollinated, it will spend the next 6 to 9 months producing fruit and seeds. If it is not pollinated, the flower will collapse and in a few months a leaf will appear again.
Typically it takes the plant two to three years to recover before it is able to flower again. If you hear about a Titan arum blooming in the area, I highly recommend taking the time to see it. It is truly an awesome sight, not just because of the smell, but the size too. If you would like to see pictures of the U of I Titan arum, check out Facebook under "Friends of the University of Illinois Conservatory".