Also called:
corpse flower
Related Topics:
flower
inflorescence

titan arum, (Amorphophallus titanum), herbaceous flowering plant of the arum family, known for its massive foul-smelling inflorescence (cluster of flowers). The plant is endemic to the steep hillsides of rainforests in western Sumatra but is cultivated in botanic gardens worldwide. The unusual short-lived flower structure is the largest unbranched inflorescence of any plant and smells of rotting flesh. Usually taking 4–10 years or more between flowerings, a titan arum is often a major tourist attraction when in bloom.

Taxonomy

See also list of plants in the family Araceae

Inflorescence

Like other members of the arum family, the massive inflorescence of the titan arum consists of an inner flower spike, known as a spadix, surrounded by a petal-like collar known as a spathe. The large furrowed spathe is green to cream-colored on the outside and tightly encloses the spadix before opening to reveal its deep crimson to purple interior. The upper, visible half of the spadix is smooth and yellowish to brown in color, and the entire spadix can reach more than 3 meters (9.8 feet) in height. Although the inflorescence develops over several months, with its growth peaking at a rate of up to 15 cm (6 inches) a day, it only blooms for around 24–48 hours. Hundreds of unisexual flowers are borne toward the bottom of the spadix within a protective chamber formed by the spathe and mature separately to reduce self-pollination; the dense cream-colored male flowers are located above the pink to orange female flowers. While in bloom, the structure generates heat, more than 90 °F (32 °C), and produces its characteristic carrion odor to attract flesh flies and carrion beetles for pollination.

The fertilized flowers develop into bright red to orange spherical fruits, and the spathe and the upper spadix collapse away to facilitate their dispersal, commonly by rhinoceros hornbills (Buceros rhinoceros) and other animals. Eventually the remaining structure withers and the plant goes dormant.

Venus's-flytrap. Venus's-flytrap (Dionaea muscipula) one of the best known of the meat-eating plants. Carnivorous plant, Venus flytrap, Venus fly trap
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Leaf cycle and dormancy

During the years that the plant does not flower, it usually produces a single, treelike leaf, some 4.6–7 meters (15–23 feet) tall. The petiole (leaf stalk) is speckled with white patches and typically features three branches topped with numerous large leaflets. Most of the food it produces is stored in a massive underground corm and is later used to fuel the rapid growth of the inflorescence or a new leaf following a period of dormancy. The corm can weigh around 70–90 kg (154–200 pounds) and is the largest in the plant kingdom. After 12–18 months of photosynthesis, the leaf dies back, and the plant goes dormant. Typically several leaf cycles are completed before the plant has enough stored energy to flower again.

Other superlative species

The largest single flower belongs to the unrelated monster flower (Rafflesia arnoldii), also of Indonesia.

The largest branched inflorescence is that of the talipot palm (Corypha umbraculifera), native to India and Sri Lanka.

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Araceae, large family of flowering plants (order Alismatales) comprising more than 4,000 species in over 140 genera. Members of Araceae occur worldwide but are most common in the tropics. The family includes many climbers and herbaceous plants as well as rooted or free-floating aquatics. Colloquially known as aroids, members of the family include a number of common houseplants and cut flowers used in the floral industry. See also list of plants in the family Araceae.

Physical description

Araceae species are monocotyledons, meaning that each of their seeds has a single cotyledon (embryonic seed leaf). Most members of the family have leaves with a distinct petiole and an expanded blade that is uncharacteristically reticulate among the monocots. The leaves typically contain calcium oxalate, which may form stinging needle-shaped crystals known as raphides.

Members of the family are characterized by an unusual inflorescence. The minute flowers are bisexual or unisexual and are densely packed onto a generally thickened spike known as the spadix. This in turn is usually accompanied or surrounded by a leafy or fleshy bract known as the spathe. In the cultivated Anthurium, the spadix consists of bisexual flowers, whereas in the voodoo lily (Amorphophallus konjac), the spadix consists of three parts: a basal section with female flowers, a central portion with male flowers, and a long sterile tip that produces the characteristic odour of rotting flesh upon maturing.

Remarkably, a number of species are thermogenic, meaning they can generate heat. Species such as cuckoopint (Arum maculatum) and titan arum (Amorphophallus titanum) can warm their inflorescences while flowering and can maintain temperatures higher than and independent of the ambient temperature. This is accomplished by a specialized pathway of the mitochondria within the cells. It is thought that this ability may protect against tissue damage in cold regions and helps attract pollinators. Many of these plants also emit a fetid odour, which, together with the heat, mimics rotting animal flesh to attract carrion beetles, flesh flies, and other insects for pollination.

Major genera and species

There are eight recognized subfamilies of Araceae: Aroideae, Gymnostachydoideae, Lasioideae, Lemnoideae, Monstereae, Pothoideae, Orontioideae, and Zamioculcadoideae. The largest of these is Aroideae, with more than 2,500 species across 75 genera. Common genera include ArumArisaema (including jack-in-the-pulpit [A. triphyllum]), Calla, Colocasia (such as taro [C. esculenta]), and Philodendron. The enormous titan arum (Amorphophallus titanum) has a massive foul-smelling inflorescence that is one of the largest on Earth. Water lettuce (Pistia stratiotes) is an aquatic species.

Another large subfamily is Pothoideae, with more than 900 species mostly distributed in Anthurium and Pothos. The taxonomy of Monsteroideae is contentious, with anywhere from 380 to more than 700 species listed. These include the familiar peace lilies (Spathiphyllum) and Monstera houseplants as well as the genera RhaphidophoraRhodospathaScindapsus, and Stenospermation.

The extremely reduced duckweeds (Lemna and its relatives) are specialized aquatic members of the Araceae family found in the small subfamily Lemnoideae. Lasioideae has 10 genera and nearly 60 pantropical species. The nearly 30 species of Zamioculcadoideae are restricted to central Africa. Orontioideae, found in temperate East Asia and temperate North America, contains three genera and six species, including the skunk cabbages Symplocarpus foetidus and Lysichiton americanus. Gymnostachydoideae contains a single species, Gymnostachys anceps.

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