Amorphophallus titanum, known as the titan arum, is a flowering plant with the largest
unbranched inflorescence in the world. The titan arum's inflorescence is not as large
as that of the talipot palm, Corypha umbraculifera, but the inflorescence of the talipot palm
is branched rather than unbranched. Due to its odor, which is reminiscent of the
smell of a decomposing mammal, the titan arum is characterized as a carrion flower, and
is also known as the corpse flower, or corpse plant. For the same reason, the title corpse
flower is also attributed to the genus Rafflesia which, like the titan arum, grows in the rainforests
of Sumatra.
Distribution Amorphophallus titanum is endemic to western
Sumatra, where it grows in openings in rainforests on limestone hills. The plant is cultivated
by botanic gardens and private collectors around the world.
Description
The titan arum's inflorescence can reach over 3 metres in height. Like the related cuckoo
pint and calla lily, it consists of a fragrant spadix of flowers wrapped by a spathe, which
looks like a large petal. In the case of the titan arum, the spathe is a deep green on
the outside and dark burgundy red on the inside, with a deeply furrowed texture. The spadix
is hollow and resembles a large loaf of French bread. Near the bottom of the spadix, hidden
from view inside the sheath of the spathe, the spadix bears two rings of small flowers.
The upper ring bears the male flowers, the lower ring is spangled with bright red-orange
carpels. The "fragrance" of the titan arum resembles rotting meat, attracting carrion-eating
beetles and flesh flies that pollinate it. 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 perfume volatilize;
this heat is also believed to assist in the illusion that attracts carcass-eating insects.
Both male and female flowers grow in the same inflorescence. The female flowers open first,
then a day or two following, the male flowers open. This usually prevents the flower from
self-pollinating. After the flower dies back, a single leaf,
which reaches the size of a small tree, grows from the underground corm. The leaf grows
on a somewhat green stalk that branches into three sections at the top, each containing
many leaflets. The leaf structure can reach up to 6 metres tall and 5 metres across. Each
year, the old leaf dies and a new one grows in its place. When the corm has stored enough
energy, it becomes dormant for about four months. Then, the process repeats.
The corm is the largest known, typically weighing around 50 kilograms. When a specimen at the
Princess of Wales Conservatory, Kew Gardens, was repotted after its dormant period, the
weight was recorded as 91 kilograms. In 2006, a corm in the Botanical Garden of Bonn, Germany
was recorded at 117 kilograms. Cultivation
The titan arum grows in the wild only in the equatorial rainforests of Sumatra, Indonesia.
It was first scientifically described in 1878 by Italian botanist Odoardo Beccari. The plant
flowers only infrequently in the wild and even more rarely when cultivated. It first
flowered in cultivation at the Royal Botanic Gardens at Kew in London, in 1889, with over
100 cultivated blossoms since then. The first documented flowerings in the United States
were at New York Botanical Garden in 1937 and 1939. This flowering also inspired the
designation of the titan arum as the official flower of the Bronx in 1939, only to be replaced
in 2000 by the day lily. The number of cultivated plants has increased in recent years, and
it is not uncommon for there to be five or more flowering events in gardens around the
world in a single year. The titan arum is more commonly available to the advanced gardener
due to pollination techniques.
The popular name "titan arum" was invented by the broadcaster and naturalist Sir David
Attenborough for his BBC series The Private Life of Plants, in which the flowering and
pollination of the plant were filmed for the first time. Attenborough felt that constantly
referring to the plant as Amorphophallus on a popular TV documentary would be inappropriate.
In 2003, the tallest bloom in cultivation, some 2.74 m high, was achieved at the Botanical
Garden of the University of Bonn in Germany. The event was acknowledged by Guinness World
Record. On 20 October 2005, this record was broken at the botanical and zoological garden
Wilhelma in Stuttgart, Germany; the bloom reached a height of 2.94 m. The record was
broken again by Louis Ricciardiello, whose specimen measured 3.1 m tall on 18 June 2010,
when it was on display at Winnipesaukee Orchids in Gilford, New Hampshire, USA. This event,
too, was acknowledged by Guinness World Records. Blooming
In cultivation, the Titan Arum generally requires 7–10 years of vegetative growth before blooming
for the first time. After its initial blooming, there can be considerable variation in blooming
frequency. Some plants may not bloom again for another 7–10 years while others may
bloom every two to three years. There have also been documented cases of back-to-back
blooms occurring within a year and corms simultaneously sending up both a leaf and an inflorescence.
There has also been an occasion when a corm produced multiple simultaneous blooms.
The spathe generally begins to open between mid-afternoon and late evening and remains
open all night. At this time, the female flowers are receptive to pollination. Although most
spathes begin to wilt within twelve hours, some have been known to remain open for 24–48
hours. As the spathe wilts, the female flowers lose receptivity to pollination.
Self-pollination is normally considered impossible, but in 1999, Huntington Botanical Garden botanists
hand-pollinated their plant with its own pollen from ground-up male flowers. The procedure
was successful, resulting in fruit and ten fertile seeds from which several seedlings
eventually were produced. Additionally, a Titan Arum at Gustavus Adolphus College unexpectedly
produced viable seed through self-pollination in 2011.
Stench As the spathe gradually opens, the spadix
releases powerful odors 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,
dimethyl disulfide, trimethylamine, isovaleric acid, benzyl alcohol, phenol, and indole.
Gallery
See also List of publicised titan arum blooms in cultivation
Footnotes
Bibliography Bown, Deni. Aroids: Plants of the Arum Family.
Timber Press. ISBN 0-88192-485-7 Association of Education and Research Greenhouse
Newsletter, volume 15 number 1. External links
In depth species information from Royal Botanic Gardens, Kew
Titan flowering at Royal Botanic Gardens, Kew
Three Webcams of Titan plus time-lapse videos at Gustavus Adolphus College in Saint Peter,
Minnesota 3D Photo of 2004 bloom at Walt Disney World
List of bloomings in the US since 1937 How to grow a Titan Arum
Titan Arum at the Flower Park Kagoshima of Kagoshima Prefecture, Japan