root, In botany, the part of a vascular plant that is normally underground. It grows downward in response to gravity, absorbs water and dissolved minerals, stores food reserves, and anchors the plant. Primary root systems have a deep sturdy taproot (in gymnosperms and dicots; see cotyledon), plus secondary or lateral smaller roots, and root hairs. Grasses and other monocots produce a shallow diffuse mass of fibrous secondary roots. Additional support (e.g., in corn and many orchids) comes from stem offshoots called adventitious, or prop, roots. Fleshy roots that store food may be modified taproots (e.g., carrots, turnips, and beets) or modified adventitious roots (e.g., cassava). Tubers, such as the potato, and rhizomes, such as ginger, are modified fleshy underground stems. Aerial roots arise from the stem and either pass for some distance through the air before reaching the soil or remain hanging in the air.