From central-peripheral to adaxial-abaxial.

Higher plants are constructed of three organs--the stem, the root and the leaf. The stem and the root have two axes, apical-basal and central-peripheral, which cross orthogonally. Leaves develop from the shoot apical meristem as lateral organs that have three different axes, apical-basal, adaxial-abaxial and right-left. Recent data point to the possibility that the adaxial-abaxial axis in the leaf is formed from the central-peripheral axis in the stem.