Final answer:
The Putnams' grievance over land in the play highlights the theme of greed and competing interests.
Step-by-step explanation:
The Putnams' grievance over land in the play refers to their dispute with another Indian tribe over the ownership of a specific piece of land. This land was claimed by both tribes under separate treaties. The significance of this conflict in the play is that it highlights the theme of greed and competing interests, showing how people can become consumed by their desire for power and possession, leading to destructive consequences.