This is the title of a recent book by Pamela Dean. Cover blurb says it's based on a traditional ballad, but unlike her novel TAM LIN (highly recommended!), it doesn't include the text of the ballad or any kind of explanatory foreword or afterword. Does anyone know what ballad this might be? I haven't read far enough into the novel to find out what the plot is actually about (the supernatural element hasn't entered the story yet, although there is a distinct oddness about the new house that "suddenly sprang up," as it were, next door). I can't find anything in the database using either "juniper" or "gentian" as keyword.