Final answer:
The red trunk of the Flowerground transport system was called the Gomisariat, as mentioned in the passage. It was part of the preparations for a family trip.
Step-by-step explanation:
The red trunk of the Flowerground transport system was called the Gomisariat. In the passage, it mentions that Mrs. Sieppe was responsible for looking after the trunk, which was also referred to as 'der gomisariat.' This trunk contained the lunch and was part of the preparations for a family trip. The passage describes the meticulous planning and organization involved in preparing for the journey.