Awww dude. Okay the Cheech-Smokey joke was too easy, but it had to be done. Odds are pretty good that savvy Dharma scientists specializing in botany and conducting experiments on a secret, unpoliced tropical island during the seventies would be cultivating a crop of stuff that would make Nancy Botwin proud. Come on, all those plants in the Orchid? Please.
So Cheech comes to the island to visit the new man in charge, stumbles on to some wild Dharma sativa, starts trippin balls, fashions a Roger bong, and well, you get the picture.