Caulicle

noun

1. In botany, a little or rudimentary stem: applied to the initial stem (more frequently but incorrectly called the radicle) in the embryo, to distinguish it from the cotyledons. Also caulicule and cauliculus.
2. A short caulis or stem, esp. the rudimentary stem seen in the embryo of a seed; -- otherwise called a radicle.
3. A small stalk or stem, especially the rudimentary stalk of a seed embryo