Titan arum

The titan arum (Amorphophallus titanum) is a flowering plant in the family Araceae. It has a large unbranched inflorescence, a tall single leaf branched like a tree, and a heavy tuber which enables the plant to produce the inflorescence. A. titanum is endemic to rainforests on the Indonesian island of Sumatra.

Its flower blooms infrequently and only for a short period, and gives off a powerful scent of rotting flesh which attracts pollinators. As a consequence, it is characterized as a carrion flower, earning it the names corpse flower or corpse plant.

The titan arum was first brought to flower in cultivation at the Royal Botanic Gardens, Kew in 1889. Since then it has flowered at many botanic gardens. It remains difficult for amateurs to cultivate, but one flowered at Roseville High School in California in 2011. Flowerings can attract crowds of thousands of visitors, and in the 21st century also thousands on Internet live streaming.

A. titanum derives its name from Ancient Greek (ἄμορφος amorphos, "without form, misshapen" + φαλλός phallos, "phallus", and Τιτάν Titan, "titan, giant"). The common name corpse flower is translated from the Indonesian name bunga bangkai with the same meaning.

The name "titan arum" is said to have been coined during the filming of David Attenborough's The Private Life of Plants as the generic name Amorphophallus was considered to be "too rude" for television audiences.

A single leaf, the size and shape of a small tree, grows from the seed. The leaf grows on a patterned green and white petiole or stalk that branches into three sections at the top, each containing many leaflets. The leaf can reach up to 4.7 m (15 ft) tall. The trunklike petiole bearing the leaf can be "as thick as a person's thigh". Food in the form of sugars from the leaf accumulates (as starch) in an underground tuber or corm. After a period of about a year, the old leaf dies, and a new one grows in its place from the tuber.

When a leaf dies, the tuber becomes dormant for about four months. Then the plant produces another leaf, and repeats the cycle of supplying food to the tuber. This may continue for up to around seven years. The tuber is the largest of any known flowering plant; it may weigh more than 90 kg (200 lb).

After some years, when the tuber is sufficiently large, the plant develops an inflorescence instead of a leaf. This can take ten years from seed; subsequent flowerings can be more frequent, typically at intervals of three to seven years. The inflorescence can reach over 3 m (10 ft) in height. The inflorescence consists of a tall fragrant spadix of flowers wrapped by a spathe, shaped like an upside-down bell, resembling a petal. The spathe is deep green with cream-coloured specks on the outside, and dark burgundy red or maroon on the inside. Its sides are ribbed, creating a frilled edge. 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 between 450 and 5,000 small cream-coloured male flowers; the lower ring consists of the pink carpels of female flowers. Shortly before flowering, the two leaflike bracts at the base of the spathe dry up and die. The female flowers open before the male flowers to prevent self-pollination. The flowers last for 24 to 36 hours.