Such a break is known as a leaf-gap. A little above the departure of the leaf-bundle the stele again closes up only to be again broken by the departure of the next leaf-bundle.
In the megaphyllous forms, on the other hand, (Ferns) whose leaves are large relatively to the stem, the departure of the correspondingly large trace causes a gap (leaf-gap) in the vascular cylinder, as already described.
In the more highly developed lorms, as already indicated, the leaf-trace is split up into a number of strands which leave the base and sides of the leaf-gap independently.
