Below are some photos of the world's largest inflorescence, or cluster or flower :
Titan arum is a flowering plant with the largest unbranched inflorescence in the world. The largest single flower is borne by the Rafflesia arnoldii; the largest branched inflorescence in the plant kingdom belongs to the Talipot palm (Corypha umbraculifera). It thrives at the edges of rainforests near open grasslands. Though found in many botanic gardens around the world it is still indigenous only to the tropical forests of Sumatra. Due to its fragrance, which is reminiscent of the smell of a decomposing mammal, the titan arum is also known as a carrion flower, the "Corpse flower", or "Corpse plant". Wikipedia : Titan Arum, more details about the plant
Isn't it an amazing and funny flower ...?! Imagine the smell.