Poor Reuben seems to have a pension for being caught in the middle of controversy. Oldest child problems I guess.

You can read more about the mysterious mandrake plant here, but basically it was (and still is in certain pagan circles) superstitiously considered to have fertility-enhancing qualities. Whether Reuben knew that or not is up for question, but the bartering that went on as a result of his findings was pretty serious. When Rachel requests the plant from Leah, her sister is incensed momentarily, but notices an opportunity to make a deal. As a result, Leah gets pregnant AGAIN, and Rachel chews on a weird looking root.