PACS. 68.35.Ct -Interface structure and roughness. PACS. 68.35.Fx -Diffusion; interface formation. PACS. 89.75.Da -Systems obeying scaling laws.Abstract. -We present experimental results for the dynamical scaling properties of the development of plant calli. We have assayed two different species of plant calli, Brassica oleracea and Brassica rapa, under different growth conditions, and show that their dynamical scalings share a universality class. From a theoretical point of view, we introduce a scaling hypothesis for systems whose size evolves in time. We expect our work to be relevant for the understanding and characterization of other systems that undergo growth due to cell division and differentiation, such as, for example, tumor development.c EDP Sciences