flowers coloring

 When flowers change colors with food coloring, Why the color water dispersed in the outmost of the petals and leaves?








Most plants "drink" water from the ground through their roots. The water travels up the stem of the plant into the leaves and flowers where it makes food. When a flower is cut, it no longer has its roots, but the stem of the flower still "drinks" up the water and provides it to the leaves and flowers.


There are two things that combine to move water through plants -- transpiration and cohesion. Water evaporating from the leaves, buds, and petals (transpiration) pulls water up the stem of the plant. This works in the same way as sucking on a straw. Water that evaporates from the leaves "pulls" other water behind it up to fill the space left by the evaporating water, but instead of your mouth providing the suction (as with a straw) the movement is due to evaporating water. This can happen because water sticks to itself (called water cohesion) and because the tubes in the plant stem are very small (in a part of the plant called the xylem). This process is called capillary action.

Coloring the water with food coloring does not harm the plant in any way, but it allows you to see the movement of water through the roots to the shoots. Splitting the stem simply proves that the tiny tubes in the stem run all the way from the stem to the petals of the flowers.


The color changes through plant transport. The plant absorbs the colored water through the tissues in its stem, which pulls the water through the plant by forming a hydrogen bond with the water molecules. This hydrogen bond creates a string of water molecules that travel up the stem and out to the leaves and flowers of the plant. In this case, the colored water is dispersed in the outermost tips of the petals and leaves, where transpiration occurs.