Apostrophe is a figure of speech where the speaker directly addresses someone or something that is absent, dead, or inanimate. In this case, Crapsey directly addresses the "dead graveyard," personifying it as a recipient of her thoughts and feelings.
Here's an example from the poem:
> "Dead graveyard underneath my window,
> Tell me, what have you seen,
> In all your years of watching the seasons?"
Crapsey is clearly speaking directly to the graveyard, even though it cannot respond. This is a classic example of apostrophe, used to create a sense of intimacy and directness with the subject.