Where did those potted plants come from?

No one can quite explain the three-dozen plants in the swimming pool atrium. They just materialized during the 40 years since the pool was built.

Jonathan Richardson, who tends the tropical menagerie, says he knows the provenance of the 10-foot Norfolk pine. That came as a donation from an office of a local grocery store, along with a new, bigger pot to put it in.

Some plants may have come from classrooms and offices in…