midrib

The central or principal vein of a leaf.

In botany, the middle (often the only) rib or nerve of a leaf; a continuation of the petiole, extending from the base to the apex of the lamina. See nervation.

In apiculture, the septum or partition between the two sheets of cells which are found in every comb. Phin, Dict. Apiculture, Int., p. xiii.

A continuation of the petiole, extending from the base to the apex of the lamina of a leaf.

The strengthened vein down the middle of a flower petal or leaf.

the vein in the center of a leaf