The slowest cactus?
The Saguaro cactus (Carnegiea gigantea), found in south-western United States, does not grow branches until it is 75 years old! It is such a slow grower that in its first decade of life it grows to barely 1in (2.5cm) in height. At around 200 years, towards the end of its life, it can top 50ft (15.2m).
During the ‘dry’ season, the plant ‘collapses’ as its water is used up. However, the roots extend outwards rather
than downwards, so they take in a large quantity of water when the rains come. Then the plant can quickly absorb a ton or more of water. The Saguaro cactus is rapidly disappearing from the Arizona and Mexican deserts through destruction – by rodents, searching for the water stored within the plant.