I looked up the form because there is a new contest that requires it, and this is what PS says:
Example
Fields we have planted
have ripened slowly to golden husk.
soon they will be harvested.
the air rich with wheaten musk
the fields once more return to dust.
I am confused about the example they picked: "Planted" and "harvested" do not rhyme, and "dust" is not a rhyme to "husk"/"musk".
Does the quintain have to rhyme? If so, why do they pick an example that clearly doesn't? Or is that computer generated and picks anything a poet classified as the form, even if it doesn't actually adhere to the rules?