Just off the Thames in Southwest London, a prehistoric type of South African palm tree has been living for almost two centuries. Growing an inch a year, today it’s the height of a double-decker bus and slopes drunkenly 16 feet to the side. It needs four metal crutches to keep from falling over altogether—for an expat at least 249 years old, not bad. The tree, an Eastern Cape giant cycad, is kept in the Palm House at the Royal Botanic Gardens of Kew—an enormous, Victorian glass greenhouse and steamy Noah’s…
