In my experience and from what i have read. polipoid is this a plant that contains 2 sets of cromosomes in each cell, making it a bigger higher producer plant.
when babys instead of developing 2 cotiledons, they produce 3 or 4, so when the real leafs, come out, instead of 2, they get 3 or 4, so they grow much bigger, much thicker, many more branchs and lots more stuff..... EXTREAMLY hard to get one, but if you do, give all the love a boy can give!!!!

what Loc says is part truth, the chemical given to plants to produce polyploids is colchisine.

Anyways its extreamely rare, to find a natural seeds that produces a polyploid, almost impossible, this is mustly from treated species....