At the beginning of the 20th century, a physics professor in Massachusetts inherited a ton of money. He promptly headed for the South Pacific, settling there and founding what’s now the Harrison Smith Botanical Garden. Maybe Smith had a slight Noah complex: He brought in plants from around the world, which means an African flower might sit next to a South American fern. The problem is that he inadvertently killed off the native plants with his imports. Still, the garden is a lovely spot to wander around, a sampler box of world botany.