The Bald Cypresses of Frankfurt Zoo

Five trees from the swamps of North America have spent a century and a half beside a pond in Frankfurt Zoo. The city puts the bald cypresses on the shore of the Grosser Weiher at 150 to 170 years old, and the largest of them measures 6.90 metres round. The largest also shows the species' strangest habit. Around its base rise knee roots, hollow outgrowths pushing up from the ground. Where a bald cypress stands with its roots in water, as it does in the swamps it comes from, the knees exchange gas for the roots below. The city says they are clearly visible on this tree. It is a conifer that behaves like a broadleaf. In autumn the soft needles turn copper red, and then the whole tree drops them and stands bare through the cold months. The species can reach 30 metres, but nobody has published the height of these five, and only the largest has a recorded girth. No planting year is given either, so the age stays a range. They are entry 018 on Frankfurt's register of natural monuments, and they stand inside the zoo, so seeing them takes a ticket. Adults pay 12 to 13 euros, the reduced rate is 6 euros, and children under six go free. The zoo opens every day of the year, from 9:00 to 17:00 on its winter hours. The Zoo U-Bahn station is near the entrance, though we have not timed the walk to the pond.