What is the name of the Elvish waybread that Frodo and Sam keep in their pack?

The Elvish waybread carried by Frodo and Sam is lembas bread. In Tolkien’s Middle-earth, lembas is a compact, nourishing travel food made by the Elves and wrapped in leaves to preserve it.

The Fellowship receives lembas from the Elves of Lothlórien after leaving Caras Galadhon. Its special value becomes clear during the journey through Mordor: small portions sustain Frodo and Sam through long marches, hunger, and exhaustion when ordinary provisions are scarce.

Tolkien describes lembas as more than ordinary bread. It is associated with Elvish care, secrecy, and endurance, and it was traditionally given to travelers only with permission. Sam’s careful management of their remaining supply becomes an important detail as the pair approach Mount Doom.

Several names in the question’s options belong to different parts of Tolkien’s mythology. Laurelin and Telperion were the Two Trees of Valinor, while athelas is a healing herb associated with Aragorn. Lembas is therefore the specific and canonical answer for the Elvish waybread in The Lord of the Rings.