ha ha, that's one I haven't heard before.
Can't link to it directly from here, but cut and pasting it will work.
That was from a skit on "Rowan & Martin's Laugh-In" in either 71 or 73. The standard segment would always start, "A poem, by Henry Gibson." The meek character would always come out carrying an over sized daisy (or sunflower ) and would then tell a humorous ( they hoped) short poem. Then one week the Duke himself came out and did this poem, same set up as the standard character. The Duke even had the flower.
Here's a good description of the segement;
http://en.wikipedia.org/wiki/Henry_Gibson