A spooky story about a spooky poem

I used to work as ~~an intern at nickelodeon~~ a freelance archeologist, when I came across something, rather ancient and undatable. It was a slab of substance covered in a layer of Darkanium (one proton off from being Sanicite). The slab was scrawled with green markings that I couldn't decipher. Luckily, I was able to decipher the markings.

Warning:

The following text is extremely volatile, and has been known to cause: Fevers, Headaches, Migraines, Cataracts, Cysts, Autism, Genital Herpes, Liver Failure, Stroke, Heart Attacks, Ebola, Violent Vomiting and Explosive Diarrhea. The markings have also been reported to have summoned Patrixxx among recitation. If you happen to have psychic powers or a sensitive anus, please ignore the following text.
>Roses are red
>Violets are blue
>Why is my text green?
>I bet the jews did this
You're probably wondering why I said, "Used to work as"
Well, DATS BECUZ IM DED