You don't cite poetry, you attribute it. The word "cite" implies you are doing some research and are referencing a respected source of information to prove a point or support an idea. If you are using a poem that someone else wrote, you attribute it to them to give them the credit for writing it (rather than incorrectly taking the credit yourself for poetry you didn't write).
You have two choices
1) You can either claim the poetry as your own. You wrote it. It is yours. You can just say so.
2) You can attribute the poem to a pseudonym. There is nothing wrong with doing this (since you can't steal your own original work), many accomplished poets have done published their own works under a fake name.
Just attribute the poem to the pseudonym and provide a link to any website.