Without flowers, many plants would not be able to reproduce   and many insects would not be able to get enough food to live. Here are some interesting facts about flowers plants. * Most plants grow flowers each year, but some take much longer. The century plant   grows only one flower and then it dies! Even more amazing is a plant from South America called Puya raimondii. It doesn't grow a flower until it is 150 years old, and after that it dies, too. * The smallest flowering plant in the world is thought to be the common watermeal  . Its leaves are only 1mm across! * Bamboo has amazing flowering habits. There are many different kinds of bamboo in the world. And they have different flowering habits. A few flower each year, but most wait much longer. What is amazing is that all bamboo of the same kind will flower almost at the same time, where it is 6 growing! Nobody knows why. * The white flower of the Amazon water lily  is the size of a football, and the flower turns purple after it has been pollinated  . * The Caucasian lime can grow in Britain. Its flowers are _ to bees. If they touch the flowers, they will die. Which of the following plants needs the longest time to grow flowers?
The bamboo. The watermeal. The Puya raimondii. The Caucasian lime.