The Batang Palupuh Nature Reserve, 16km north of Bukittinggi, is home to many orchid species, as well as the massive Rafflesia arnoldii and Amorphophallus titanium, the largest flowers on the planet – the latter endemic to Sumatra. The rafflesia blooms throughout the year, if briefly, whereas you have to be incredibly lucky to catch the Amorphophallus in bloom at all. Both flowers reek like roadkill. Local buses to Palupuh cost 8000Rp and hiring a guide to lead you to the flowers is around 100,000Rp.
The blossom of the parasitic rafflesia measures nearly a metre across and can weigh up to 11kg, while the inflorescence of Amorphophallus can extend to over 3m in circumference.