AbstractThe Arabidopsis root, with its ordered cell divisons and straightforward patterning, is a tractable model for understanding organ formation during plant development. Regular cell divisions in the root tip produce consistent cell type arrangements that can be followed through time. Root development occurs through the precise spatiotemporal control of transcription factors and phytohormone signaling networks. In this article, we provide a broad overview of the major events controlling embryonic and post‐embryonic development within each major tissue and cell type in the primary root of Arabidopsis. WIREs Dev Biol 2012 doi: 10.1002/wdev.49For further resources related to this article, please visit the WIREs website.