Pitcher of Nepenthes is formed from\tLeaf bases\tLamina\tpetiole\tLeaf apex

Answer is 4 i.e Leaf Apex. From the stems of Nepenthes arise alternate, sword-shaped leaves with entire leaf margins. An extension of the midrib (the tendril), which in some species aids in climbing, protrudes from the tip of the leaf; at the end of the tendril the pitcher forms