[Eruanna]

V

"Verily this is a sapling of the line of Nimloth the fair; and that was a seedling of Galathilion, and that a fruit of Telperion of many names, Eldest of Trees. Who shall say how it comes here in the appointed hour? But this is an ancient hallow, and ere the kings failed or the Tree withered in the court, a fruit must have been set here. For it is said that, though the fruit of the Tree comes seldom to ripeness, yet the life within may then lie sleeping through many long years, and none can foretell the time in which it will awake. Remember this. For if ever a fruit ripens, it should be planted, lest the line die out of the world. Here it has lain hidden on the mountain, even as the race of Elendil lay hidden in the wastes of the North. Yet the line of Nimloth is older far than your line, King Elessar."

from The Steward and the King RotK

Gandalf gives Aragorn some pertinent advice.