Thanks to NEWFOUNDLANDER's jogging my memory with the violets line, I remembered the flower name which the old folks used in my neck of the woods when I was learning my music: "And the pale Amaranthus with violets of blue." Amaranthus (sometimes called Pigweed by less romantic folks) is a fairly common wildflower, but it is also a name given to a mythical flower which was supposed never to fade. Tennyson refers to it in one of his poems, I believe.