Collateral Bundle
Bicollateral Bundle
A single patch of phloem is present.
Two patches of phloem are present.
Xylem lies on the inner side and phloem on the outer side.
Xylem is present in the centre with phloem present on both its sides.
Can be open or closed and contains a single strip of cambium if open.
It is generally open and contains 2 strips of cambium (outer and inner).
