At the beginning of 2014, two states opened the floodgates for the marijuana trade, as both Washington and Colorado legalized its sale, possession, and consumption for recreational purposes.

Yet there continues to be one major threat to the industry that's making it tough for participants to stay on the right side of the law even in states like these. In the following video, Motley Fool contributor John Maxfield, the author of a recent in-depth series on the industry, digs into the problem that the U.S. tax code is presenting to burgeoning cannabis entrepreneurs.