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.
The seeds were planted and subsequently germinated. Unfortunately, there is no trace of the plants grown from that seed, which would have been of great interest to the species collectors.
Ed. Lerman, J. C. and E. M. Cigliano. 1971. New carbon-14 evidence for six hundred years old Canna compacta seed. Nature 232: 568--570