FIGURE 2.2 Schematic of the cellular organization of the Arabidopsis root. (A) Median longitudinal section of a length of the root. e dierent developmental stages and the direction of cellular maturation are noted. Inset: the stem cell niche includes the quiescent center and the adjacent initial cells. (B) Median longitudinal section of the root tip. (C) Transverse cross section within the dierentiation zone. e dierent cell types comprising the stele (A) are detailed in (B) and (C). is drawing is not to scale.