Rafflesia

a genus of plants of the family Rafflesiaceae. The plants parasitize the roots and stems of a number of tropical plants of the family Vitaceae, especially the genus Cissus, that grow in the tropical rain forests of Indonesia and the Philippines. The Rafflesia lack roots and leafy stems. The flat, spreading flowers form on a host plant and consist of five very large, fleshy perianth bracts, which originate from a central cup-shaped area that is surrounded by a thick ring.

There are 12 species of Rafflesia. The best-known is the monster flower (R. arnoldi), which grows on Sumatra. Its flower is the largest known flower in the world. The flower bud resembles a cabbage head, and an open flower reaches a diameter of 1 m and a weight of 4–6 kg. The flowers emit a strong fetid odor that attracts flies for pollination.