Possible Clues:

• Verse often beginning 'There once was a ...'
• Writing that's often obscene
• Irish poem or Saskatchewan hamlet
• Green wrench, though it's often blue
• Often at its start there was (in quotes) fruit twist
• Poem with a punch line
• Humorous poem from the Treaty City?
• Often-bawdy verse
• Humorous verse of 5 lines
• In Ireland this may be rude inversely