Rafflesia arnoldii produces the world’s largest single flower, with exceptional blooms reaching about 1 metre across. It is native to the rainforests of Sumatra and Borneo in Southeast Asia.
This species is a parasite rather than a typical green plant. It has no visible stems, leaves, or roots, and obtains water and nutrients from host vines in the genus Tetrastigma. Much of the plant remains hidden inside its host until a large bud emerges and opens.
The flower is reddish-brown and covered with pale spots. Its strong smell of rotting meat attracts carrion flies, which can transfer pollen between flowers. A bloom lasts only several days, making sightings relatively unusual.
Rafflesia arnoldii is often confused with the titan arum, another giant Indonesian flowering plant. The titan arum has the world’s largest unbranched inflorescence, not the largest single flower. Rafflesia’s unusual parasitic lifestyle also makes it distinct from ordinary rainforest plants.