In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. However, this is not always the case, a root can also be aerial (growing above the ground) or aerating (growing up above the ground or especially above water). Furthermore, a stem normally occurring below ground is not exceptional either (see rhizome). So, it is better to define root as a part of a plant body that bears no leaves, and therefore also lacks nodes. There are also important internal structural differences between stems and roots.
The first root that comes from a plant is called the radicle. The four major functions of roots are 1) absorption of water and inorganic nutrients, 2) anchoring of the plant body to the ground, and supporting it, 3) storage of food and nutrients, 4) vegetative reproduction. In response to the concentration of nutrients, roots also synthesise cytokinin, which acts as a signal as to how fast the shoots can grow. Roots often function in storage of food and nutrients. The roots of most vascular plant species enter into symbiosis with certain fungi to form mycorrhizas, and a large range of other organisms including bacteria also closely associate with roots.
Famous quotes containing the word root:
“Flower in the crannied wall,
I pluck you out of the crannies,
I hold you here, root and all, in my hand,
Little flowerbut if I could understand
What you are, root and all, and all in all,
I should know what God and man is.”
—Alfred Tennyson (18091892)
“The root of the problem is not so much that our people have lost confidence in government, but that government has demonstrated time and again its lack of confidence in the people.”
—Jimmy Carter (James Earl Carter, Jr.)
“Under an oak, whose antique root peeps out
Upon the brook that brawls along this wood.”
—William Shakespeare (15641616)