In My Mortal Enemy, Myra Henshawe is referring to this poem ("Lyrische Intermezzo," no. 62, beginning "Am Kreuzweg wird begraben") when she asks Nellie Birdseye to recite Heine's poetry about the "poor-sinner's flower." (See March 347)
In The Song of the Lark, Thea Kronborg recites the text (Heine's "Lyrisches Intermezzo," no. 45, beginning "Im leuchtenden Sommermorgen"; the first word should actually be "Am" ). The German is followed by a parenthetical translation: "in the soft-shining summer morning...."