A Chicago-based intellectual property firm launched a practice group dedicated to cannabis businesses, entering a rapidly growing marketplace.McDonnell Boehnen Hulbert & Berghoff LLP partners George “Trey” T. Lyons III and Nicole E. Grimm, the new practice group’s co-chairs, have worked on intellectual property matters for cannabis companies for almost four years, attempting to dispel rampant misinformation in the field. But the firm did not move to make the practice an official specialty area until …