The elder of the Two Trees of Valinor, called the White Tree, which shed silver light on the domain of the Valar. His leaves were of dark green, shining silver beneath, and his boughs were decked with brilliant flowers that shed a rain of silver dew.
In the published Silmarillion, there's no hint as to the length of the Years of the Trees (except a rather vague reference to 'long ages'). However, a document does exist that gives more precise measurements, The Annals of Aman. That is the source of the precise figure of 14,322 years, though it should be said that this unpublished figure was subjected to extensive editing, and should not be considered completely reliable.
Curiously, though Telperion is a Quenya name, the word telpë, 'silver', is an element from the Telerin language. It was said to have been chosen over the Quenya word tyelpë because of the particular delight that the Teleri had in silver, prizing it even over gold.
The full etymology of Telperion is unclear. It has been suggested that it contains the root-word rig, 'crown'. This is entirely possible (the same root is known to appear in the name Celebrían, for example) but this cannot be stated with certainty.