I looked up the origins of this type of grave markers and found a website about the Woodmen of the World.
The largest fraternal benefit society with open membership in the United States, Woodmen of the World was founded in Omaha, Neb., by Joseph
Cullen Root on June 6, 1890. From its humble beginnings more than a
century ago, Woodmen of the World has grown into a financial services
organization large enough to offer security, but small enough to still
care about each individual member.
Woodmen gravestones were originally intended to be a uniform design sent by the Home Office to local stonecutters, but not all the cutters followed the design. Some used their own interpretation of the Woodmen design which they felt was more appropriate.
The result was a wide range of designs that reflected members' personal
tastes and included elements that were symbolic of Woodmen ceremonies or rituals. A tree stump, part of the Society's logo, is the most common symbol used on gravestone designs. Many stand approximately four to five feet high. In one Kentucky cemetery, the gravestones started out as a modest Woodmen stump and grew larger with each additional burial. One gravestone is three feet wide with seven branches.