A vascular cambium is a lateral meristem. In three dimensions, it forms a hollow cylinder with the xylem to the inside and phloem to the outside. In Medicago, it forms in two regions, which connect to form a continous tissue layer. Fascicular cambium forms from procambium between the primary phloem and primary xylem. Interfascicular cambium, forms from ground meristem inthe region between the vascular bundles.