Meristems

The shoot and root tips are apical meristems (located at the apex of organs). They give rise to three primary meristems: protoderm, procambium, and ground meristem. These in turn give rise to the mature primary tissues. 

Secondary meristems differentiate within primary tissues and give rise to secondary tissues.

Coleus shoot tip, note primary meristems,  leaf primordia, axillary bud meristems, and intercalary meristem regions.

Root tip, note root cap and primary meristems.

Secondary Meristems

Diagrammatic representation of herbaceous dicot stem vascular bundle, note the vascular cambial zone.

Micrograph of herbaceous dicot stem vascular bundles, note cambial zone.

Development of the periderm (in this case developing from cortical cells).