While the zoo is more famous for its animals, it is also a botanical garden and boasts some remarkable plants. Among them is a member of the bromeliad family called Puya, which comes from the Mapuche Indian word meaning "point".
The flower spike is several metres tall and covered in turquoise flowers with bright orange anthers.
Giles Palmer, curator of plants and gardens at the zoo, said: "They can take 15 years to flower and are often monocarpic, meaning they die after flowering and setting seed. Most Puya in cultivation are accidental hybrids - they cross pollinate readily - so we can't give it a species name, but it's a very impressive plant."
The zoo is holding an evening garden tour on 20 July, where visitors will be able to view some of the 2,500-strong plant collection including banana trees, gunnera and the giant lily pads in Crocodile Swamp.