According to this site:
http://www.cuteandweird.com/2009/10/worlds-oldest-trees-photos/ these are the oldest ones:
Sweden claims that it has the oldest tree, about 10,000-year-old spruce. It is located in the Dalarna province.
Methuselah tree – 4,789 years old, is a Great Basin Bristlecone Pine (Pinus longaeva) in the White Mountains of California.
Sarv-e-Abarkooh Tree – One of the oldest tree in the world that dates back to 4500 years ago located in Abarkouh, Yazd province, center of Iran.
Llangernyw Tree – 4,000 years old tree located in a rural village in Conwy county borough, north Wales.
Alishan Sacred Tree – 3,000 years old, located in the mountains of Chiayi County in Taiwan.
Chestnut Tree of One Hundred Horses – believed to be 2,000 to 4,000 years old. It is the largest and oldest known chestnut tree in the world located on the eastern slope of Mount Etna in Sicily, Italy.
Bodhi Tree – 2,300 years old. The tree is a large and very old Sacred Fig tree located in Bodh Gaya about 100 km (62 mi) from Patna in the Indian state of Bihar.
Jomon Sugi Tree – 2,170 – 7,200 years old — a large cryptomeria tree located on Yakushima, a UNESCO World Heritage Site, in Japan.