Splayed obscenely on the forest floor, it looks like an alien delicacy, an exotic organ meat harvested from some extraterrestrial beast and left to rot in the wake of an intergalactic debauch. With massive, fleshy petals — the entire flower may be 3 feet across — and a perfume evocative of putrefying meat, it's hardly believable that Rafflesia arnoldii is a member of the plant kingdom. Indeed, there are no vegetative structures in evidence.
These lurid blossoms, the largest in the world, seem to have erupted — blossomed seems too delicate a description — ex nihilo. But a plant it is, albeit a highly unusual one. It is a parasite, supported by three species of Tetrastigma vine, a tropical relative of the grape.
R. arnoldii and its approximately 30 relatives lurk beneath the canopies of tropical rainforests from Thailand to Malaysia, Indonesia, and the Philippines. Also called corpse flowers, they differ from another species known by that name: Amorphophallum titanum, or the titan arum, a relative of the calla lily familiar from floral arrangements. Titan arums boast the world’s largest unbranched inflorescences — massive, phallic structures boasting thousands of miniature flowers." Most Rafflesia are endemic to a single island and some are known from only one or two sites. All species are reliant on Tetrastigma vines as their hosts.
“They are very picky,” says Siti Hidayati, a plant ecologist and lecturer at Middle Tennessee State University who has studied the plant in her native Indonesia. “Of the approximately 90 species of Tetrastigma, only about ten host Rafflesia.”
