'Foliar gap' definitions:

Definition of 'Foliar gap'

From: GCIDE

Foliar \Fo"li*ar\, a. (Bot.) Consisting of, or pertaining to, leaves; as, foliar appendages. [1913 Webster]
Foliar gap (Bot.), an opening in the fibrovascular system of a stem at the point of origin of a leaf.
Foliar trace (Bot.), a particular fibrovascular bundle passing down into the stem from a leaf. [1913 Webster]