Difference between Punkin and Pumpkin

What is the difference between Punkin and Pumpkin?

Punkin as a noun is pumpkin. punkin is an alternative form and pronunciation used sometimes in the united states, especially as a term of endearment or diminutive. james whitcomb riley, poem "when the frost is on the punkin" [http://www.bartleby.com/104/10.html] while Pumpkin as a noun is a domesticated plant, cucurbita pepo similar in growth pattern, foliage, flower, and fruit to the squash or melon.

We hope you now know whether to use Punkin or Pumpkin in your sentence.