Trees... from the Moon

"Stuart Roosa's love of the outdoors prompted him to choose tree seeds as one ingredient of his Personal Preference Kit, the sock-sized pouch Apollo astronauts were allowed to fill with their prize possessions. The seeds were provided by the US Forestry Service - in particular, by its then Staff Director for Forest Genetics Research, Stan Krugman."

This scenario seems like the backstory for some arboreal holocaust a la "The Day of the Triffids."