The radicle is the structure that will become the root in a mature plant. When it grows out of the seed and into the soil, it grows downward. DIAGRAM: Cotyledons / Acorn PHOTO: Seed Cross Section / Seed Cross Section
Part of the seed embryo below the cotyledons, constituting the rudimentary root; in the cocoa bean, a hard, slender stalk about one-third the length of the bean (seed) situated at the hilum (broader) end.
In botany, the radicle is the first part of a seedling (a growing plant embryo) to emerge from the seed during the process of germination. The radicle is the embryonic root of the plant, and grows downward in the soil. Above the radicle is the embryonic stem or hypocotyl, supporting the cotyledon(s).