Rafflesia

Rafflesia is a genus of unusual flowering plants found naturally in tropical Southeast Asia, especially on the islands of Sumatra and Borneo and in parts of the Malay Peninsula and nearby regions. Rafflesia plants are holoparasites: they cannot make their own food through photosynthesis and depend entirely on a host plant for water and nutrients. Their host plants are climbing vines of the genus Tetrastigma, relatives of grapevines.

For most of its life, a Rafflesia exists as a network of tissues hidden inside its host. It has no normal leaves, stem, or roots. When it is ready to reproduce, a large bud emerges from the host and eventually opens into a flower. Some species produce flowers close to a metre across, making Rafflesia among the largest individual flowers known. The flower has a distinctive reddish-brown color and often gives off a strong odor resembling rotting meat.

This smell, together with its appearance, attracts flies and other insects that can transfer pollen from one flower to another. Rafflesia flowers are short-lived, usually remaining open for only a few days before beginning to decay. The reproductive process is difficult to observe because male and female flowers occur on separate plants, and suitable flowers may be rare in the forest.

After pollination, a fruit can develop and contain a large number of tiny seeds, although much about their dispersal and early development remains poorly understood. Rafflesia is not a single species but a group of specialized parasites, and the different species vary in flower size, appearance, and distribution. Their dependence on specific host vines and forest habitats makes them particularly sensitive to habitat disturbance.