The Great Trees of London brings together over 60 trees around the capital that have achieved "Great Tree" status - as determined by the popular tree-planting charity Trees for Cities. As you might expect, there are plenty of London planes, horse chestnuts and oaks - the everyday trees that everyone is familiar with - but also some rarer species. The Greenwich Park Shagback Hickory, for instance, probably the largest such tree in the country, and the Marble Hill Black Walnut, with its unusual pitch-black bark. There are magnificent, towering specimens, such as the Forty Hall Cedar of Lebanon and the Berkeley Square Plane, as well as humbler trees that, on first glance, might not deserve the accolade of Great. But they are special for other reasons: the Marylebone Elm is one such: it survived bombing in World War II (which destroyed the adjacent church) as well as Dutch Elm Disease in the 1970s, which wiped out three-quarters of Britain"s elms. Some incredibly venerable trees appear...