Today’s tombstone symbol is wheat, a symbol that I do not see very often on a headstone.
Wheat and other grains are some of the oldest symbols for growth and life. Wheat used to be harvested by a reaper with a scythe, which brings to mind the Grim Reaper.
On a tombstone, wheat is usually depicted as a sheaf of wheat, but is occasionally is shown as stalks of wheat.
Wheat usually symbolizes someone who has lived a long, fruitful life. Someone who has lived to a ripe old age.
Since it is a harvested grain, wheat could signify the resurrection and immortality. Or wheat may symbolize bread or the communion wafer, which are both made from wheat flour.
Finally, the obvious. Wheat carved on a tombstone could just indicate that the deceased was a farmer.