Hi,
Vascular bandle without cambium-closed vascular bandle.
In  monocot, vascular bundles have no cambium present in them. hence ,since they do not form secondary tissues they are referred to as closed.

Hope it will helpful.

Best of luck

Dear aspirant....!!

A vascular bundle without cambium is called closed. SOME VASCULAR BUNDLES THAT ARE ARRANGED CONJOINTLY DO NOT HAVE CAMBIUM BETWEEN XYLEM AND PHLOEM .THIS IS TERMED AS CLOSED VASCULAR BUNDLES.IT IS MAINLY FOUND IN MONOCOT PLANTS.