Root

In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the surface of the soil, but roots can also be aerial or aerating, that is, growing up above the ground or especially above water. Roots can be very fine like a thread or massive like those of the Sitka Spruce which, in an individual named "The Octopus Tree" at Trees of Mystery in northern California, has exposed roots over four feet thick. Read more on Wikipedia