The growth rate dispersion of needle-like beta/3 L-glutamic acid in the length direction is measured using a stagnant solution hot stage microscopy setup. Possible causes of the observed dispersion are analyzed and the resulting distribution of growth rates is used to motivate and reconstruct a distribution of an internal, growth affecting property of the crystals. The latter is then used as the initial condition for a multidimensional, morphological population balance model, whose outputs are fitted to 2D particle size distribution measurements obtained from seeded batch desupersaturation experiments. It is shown, through analysis of both types of data, that a non-zero rate of change in the direction of the new coordinate is required and a phenomenological description of this rate is proposed. The resulting model is able to quantitatively describe experimental data obtained from independent measurement devices, operating at different scales simultaneously. (C) 2015 Elsevier Ltd. All rights reserved.