Hundreds of city residents lined up for “seed share” — an exchange program that helps cannabis enthusiasts grow it at home. “It really does mark the conclusion of the D.C. Cannabis Campaign. We’ve accomplished our goals. It’s simply about the people who have been buying marijuana from the underground economy,” Adam Eidinger, head of the D.C. Cannabis Campaign, said. “If they grow it, sometime later this year they won’t have to buy it anymore from the underground economy.”