Michael PolÂlan’s best-sellÂing book, Botany of Desire, is now a film, and you can watch it online, courÂtesy of PBS. (Click to watch comÂplete film.) The film takes you inside our relaÂtionÂship with the plant world, and shows “how four familÂiar species — the apple, the tulip, cannabis and the potaÂto — evolved to satÂisÂfy our yearnÂings for sweetÂness, beauÂty, intoxÂiÂcaÂtion and conÂtrol.” AccordÂing to a piece in The San FranÂcisÂco ChronÂiÂcle, it took eight years to pull togethÂer the fundÂing for the film, and that’s simÂply because marÂiÂjuaÂna was in the mix. The film runs close to two hours. The preÂview is above, the full film is here. For more films, please visÂit our colÂlecÂtion of Free Movies Online.