Plants are a very common motif on tombstones throughout the world, though their meanings are not always so obvious.
A small selection of plants are shown below with more on the Symbolism–Plants page.
Corn is a symbol of fertility and rebirth. Corn (maize) represents all the people as well as all the things in the universe for Native Americans.
Poppies represent rest, sleep, peace, and immortality.
A fully opened Rose may indicate that the deceased died in the prime of life. The rose also signifies love, beauty and condolence. A rose bud symbolizes a life cut short and is most often found on the graves of children. A rose with a broken stem represents a life cut short. A fully opened rose with a broken stem represents the death of a mature adult.