Even though the idea would be wonderful: this is not about trees that grow on the Moon, but about trees on Earth that grew from seeds, which orbited the Moon exactly 34 times, in a small canister, during the Apollo 14 mission in 1971. For this joint project by NASA and USFS (US Forest Service), the astronaut Stuart Rosa took hundreds of tree seeds with him on this journey. Seeds of five different species of tree had been chosen: loblolly pine, sycamore, sweetgum, redwood and douglas fir. The seeds survived the weightlessness and also when the canister that contained the seeds, got destroyed in the vacuum of the decontamination chamber. The seeds had to be picked up individually after this incident.
Afterwards, the seeds were germinated by scientists and were planted in different places in the US and also in other countries. Surprisingly, this was achieved with almost all of the seeds and after a few years between 420 and 450 trees grew.
A loblolly pine was planted in the green area of the White House, some trees made it to Brazil or to Switzerland and even to Japan, in form of a gift to the Japanese Imperial Palace.
A list of trees exists, however, it was not maintained systematically and is therefore incomplete. Dave Williams from NASA has started to look for the moon trees and does now rely on the help of the general public, who might be able to offer information.
In any case, these moon trees are still growing today and remind us silently of the first lunar missions. Who knows – maybe one day, if the Moon should ever be colonized, a tree might grow up there for real? Whoever carves the name of his/her beloved into the bark, could experience celestial good luck.