Tennyson was the original poet, not a composer. Balfe set his verse to music [as Q says, an interpolated song in a much longer dramatic poem].

The song, with its talking flowers, is parodied by Lewis Carroll in the "Garden of Live Flowers" chapter of "Through the Looking Glass". Tennyson's "She is coming, my own, my sweet; Were it ever so airy a tread", is referenced in Carroll's "She is coming ... I hear her footsteps clump clump along the gravel walk."

~M~