The ArchaeoBlog has a bit about a 2000 year old date palm seed recently germinated, citing a longer article in the International Herald Tribune. The seed was found at Masada, the Jewish fortress in which the defenders killed themselves rather than surrender to the Romans.
A seed is alive, carries on respiration, and requires oxygen and food, the food coming from stored carbohydrates in the seed. Apparently it doesn't require much food, or it would be dead after 2000 years. One of the date palm seeds found there germinated, and scientists hope it grows to a mature date palm tree, which will take 30 years. The palm seed is of a species that has been long extinct, and was much praised by people in antiquity. It could have DNA for disease resistance and hardiness that has been lost during the past twenty centuries. Now that's pretty neat!