n.
In botany, the underground anchoring part of a plant.
It grows downward in response to gravity, absorbs water and dissolved minerals, and stores reserve food. 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 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 are modified, fleshy, underground stems, or rhizomes . 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.