The title, thankfully, is pretty self-explanatory. The entire event, as Dove conjures it, centers around the single word – "parsley" – that becomes the title. The historical event is, after all, called "The Parsley Massacre," because the Haitians were killed for not being able to pronounce the word. Thus the word becomes symbolic not only for the genocide itself, but for the cause of it.
Also, doesn't a poem called "Parsley" seem pretty innocent? You might expect it to be about the plant itself. This, we think, is consistent with the way that Dove treats the subject of the poem – with a kind of quiet, unexpected and understated force. She'll blindside you, and she starts right off with the title.