Which wildflower is the largest?

Rafflesia arnoldii
   The rafflesia, a parasitic plant, bears the largest flowers, up to 1 meter in diameter and weighing as much as 7 kg. A nonphotosynthetic parasite that grows on the cissus vine in southeastern Asia, the rafflesia (Rafflesia arnoldii) has no leaves or stem of its own but does produce seeds and a reddish-orange five-petaled flower. The petals are 1 inch (2.5 cm) thick and 18 inches (46 cm) long.

   The flower bud reaches maturity in about 6 months; the flower blooms for less than a week before it dies, and another blossom does not appear for 3 more years. Sometimes called the "corpse flower" or the "corpse lily," the rafflesia has a smell similar to that of rotten meat; the smell attracts flies and beetles into the plant, to pollinate it. Found almost exclusively on the island of Sumatra, the rafflesia is extremely rare.