radicle

The part of a plant embryo that develops into a root.

A small structure, such as a fibril of a nerve, that resembles a root.

In botany:

A rootlet: same as radicel.

Specifically, same as caulicle: by late writers appropriately restricted to the rudimentary root at the lower extremity of the caulicle.

In anatomy and zoology, a little root or root-like part; a radix: as, the radicles of a vein (the minute vessels which unite to form a vein); the radicle of a nerve.

In philology, same as radical, 1.

In chem., same as radical, 2.

In the graptolites, the proximal extension of the virgula.

The rudimentary stem of a plant which supports the cotyledons in the seed, and from which the root is developed downward; the stem of the embryo; the caulicle.