Raffelasia, the world's largest flower. It strongly smells like rotting meat. Around 1m diameter.
I was lucky enough to find one on Java, in the jungle. Their habitat is mostly in Sumatra.
Curiously, the smell is likened to a dead donkey, but in both trips to Indonesia, I never saw a donkey.
Useless extra fact: in the same nature reserve I also saw jungle fowl in the wild, these were domesticated and are what we now know as "chickens"