Owen Wilson OWILSON120607_02.jpg Anyone who's ever seen Owen Wilson's solar-powered mansion knows he's all about the environment - but PageSix.com says the troubled actor goes green in other ways, too!

Apparently, the Wedding Crashers star was spotted yesterday at the Green House Smoke Shop in Venice Beach buying a "small monkey pipe" for $25.

Unfortunately, someone had to be a buzzkill and snap pictures of the actor making the purchase!

According to the report, Owen flew out of the store in search of the photographer, but gave up after a few minutes - to duck behind a nearby FedEx van!

Hmm...sounds like something was decreasing Owen's motivation...but what?