original: Command Module Pilot Stuart Roosa took several hundred seeds on the mission, many of which were germinated on return resulting in the so called Moon trees.
simplifications: Pilot Stuart Roosa took several hundred seeds on the mission.  Many of seeds sprouted on return and were called Moon trees. Command Module Pilot Stuart Roosa took several hundred seeds on the mission. They were sprouted on return. They're called Moon trees. Command Module Pilot Stuart Roosa took several hundred seeds on the mission. Many of these were germinated when he returned. This resulted in the so called Moon trees. Command Module Pilot Stuart Roosa took several hundred seeds on the mission. Many were germinated on return to make the so called Moon trees. Command Module Pilot Stuart Roosa took hundreds of seeds on the mission. Many of the seeds sprouted when it returned. Stuart Roosa was a Command Module Pilot. He took several hundred seeds on the mission. Many of those seeds were germinated on return resulting in the name Moon trees. The Pilot Stuart Roosa took several hundred seeds on the mission which many germinated resulting in the so called Moon trees. Stuart Roosa who was the Command Module Pilottook several hundred seeds on the mission and they germinated to become the so called Moon trees. Stuart Roosa (Command Module Pilot) took hundreds of seeds that ended up growing on the mission, thus being called Moon Trees. Command Module Pilot Stuart Roosa took several hundred seeds to the mission, many of which were sprouted in return, resulting in the so-called Moon trees.