A true parasite (or holoparasite), the plant Rafflesia arnoldii has no stems, leaves or true roots. Instead, it spreads absorptive organ (the haustorium) inside the tissue of vines. The only part of the plant that is visible outside the host vine is the flower. The flowers smell like rotting flesh, hence it is also called a corpse flower - not to be confused with the equally odorous Titan Arum (Specimen 04-25). While the Titan Arum has the largest unbranched inflorescence (cluster of flowers arranged on a stem that is composed of one branch) in the world, Rafflesia arnoldii has the largest single flower of any flowering plant (in terms of weight).