New research by Leif Kullman at the University of Umeå is just being reported on by the media... no standing trees older than 600 years ... But below ground, the living roots of three trees gave radiocarbon dates at 5,000, 6,000 and 8,000 years BP! The oldest root system thus dates back from the end of the latest glaciation.Pretty cool stuff. Now here's the interesting question - can someone find something similar in an area that wasn't glaciated? What's the real maximum age for individuals like this?
Update: Reed E. in the comments answers that question (though, sadly, without a reference, so take this with a grain of salt)