thumb|right|250px|Seed of Scouler's willow ([[Salix scouleriana)]]
In botany, the radicle is the first part of a seedling to emerge from the seed, during the process of germination. Germination understood as a biomechanical process describes the radicle with the hypocotyl combined as the embryonic axis in the seed. The radicle emerges from a seed through the micropyle.
The emergence of the radicle is either the end or terminal part (2nd of 2 phases (or) 3rd of 3 phases ) or the 5th of 9 stages