Some flowers are so rare and only grow under specific conditions, even after decades. Jade Vine is a rare flower in the family of pea and bean. The stunningly beautiful middle mist red is the rarest flower in the world. The corpse flower is the largest and smelliest flower in the world. Yellow and purple lady slippers are the rare members of the orchid family, located mainly in London. Middlemist red is one of the rare flowers in the world.