For a more fantasy slant one could have such magical trees planted over the graves of revered royalty, the tears of the trees symbolizing the mourning of the kingdom/empire for their loss. (Perhaps the "tears" keep the bodies magically preserved so those who pay their respects can view the person as they were in life?)
For a more non magic sci-fi slant the trees could be carnivorous, existing in arid climates. During the dry seasons they would be one of the few sources of water for thirsty creatures, and then use strangling vines, or paralytic poison spines to immobilize and kill some of the animals that venture to them for nourishment. (The rotting body would provide fertilizer or the plant could be capable of engulfing and digesting it similar to the Venus fly trap.)