Although the most sensational claims for seed longevity are almost certainly bogus, seeds of Canna compacta apparently can live for at least 600 years. Viable Canna seeds were obtained from inside a walnut in a tomb in Argentina. The Canna seeds had apparently been inserted into the immature seeds of a growing walnut fruit before the hard outer shell formed. Once the shell hardened and the nut dried out, the result was a rattle. Native people strung the rattles together to form a necklace. In this case, the seeds had to be at least as old as the walnut shell, and carbon dating of the shell indicated that it was about 600 years old (Bewley and Black 1994).