Changing the Color of Flowers
Flowers get their nutrients by a process called Photosynthesis. They take in carbon dioxide (what we breathe out), sunlight, and water from the soil and turn it into oxygen and energy. The water is absorbed into the roots and travels through the vascular system in the stem to the leaves as seen in Figure 1.
Figure 1: The cross section of a flower shows where water is transferred from the root hairs, to the lateral root, to the primary root, into the vascular system and to the leaves and pedals.
By looking at Figure 1 it is evident that the vascular system is the most important component for the flower's intake of water. When flowers are bought at the store they have no roots, yet they survive without them because the vascular system is located in the entire stem.
When flowers are put into a vase full of water, after time the water level goes down. This is because the flower is "drinking" through a process called transpiration. Transpiration occurs when the water on leaves and pedals evaporates, cohesion pulls the water from the vase, up the stem, and back into the leaves and flowers. Cohesion is known as the attractive force between water molecules.