Xylem is a conducting tissue found in vascular plants in which most plant use to obtain water and minerals they need through their roots. Water and mineral moves from the soil to roots to stems and to leaves. The minerals such as potassium (K+), Calcium (Ca2+) travels in dissolved for in the water with various organic molecules supplied by root cells.
Water and minerals enter the root by different paths but converge in the stele, or central vascular bundle in roots.
Water conducting cells is known as tracheary elements.
Since bees and butterflies both pollen are flowers, the growth (population) of flowering plants would become less common without the pollen being spread.