The jackpine sonnet is: A sonnet-like poem.
"Where does it comes from? :
Milton Acorn (1923 – 1986), a poet from Prince Edward Island, created the genre and named it after the jack pine, a tree that seeds itself in fire.”
Geist Jackpine sonnet contest Rules and guidelines
"How to write one:
Write a poem with 14 lines, each line containing 7 to 13 syllables. But, in Acorn’s words, “If your sonnet cuts itself off — click! — at, say line 12, 18 or 20, leave it at that.” An odd number of lines is okay too. Apply the rhyme scheme of your choice, and if no rhyme comes up, be patient. Acorn advised writers to write internal rhymes (rhymes within a line) or external rhymes (rhymes at the end of consecutive lines) “to keep the flow.” In the absence of rhyme, use assonance (the repetition of vowel sounds), “to keep the rhyme alive in order to come up with a true rhyme further on.”