Plant cell culture is a useful technology for the production of secondary metabolites with commercial and pharmaceutical value. The rheology, morphology or aggregation of cell suspension have different applications in flow systems, bioreactor design and unit operations. This suggests solutions to mixing, mass transfer, hydrodynamic stress and cell growth problems. In this study, some morphological aspects associated with elliptical form factor and the tendency to form cell aggregates of Azadirachta indica, Borojoa patinoi and Thevetia peruviana cell cultures were evaluated in shake flasks. The rheological behavior through rheograms for cell concentrations of 0, 4, 8 and 12 g DWl(-1) was also evaluated. From this data, properties and parameters like apparent viscosity, Reynolds number, phase state and volumetric power were calculated for shake flasks of 250 and 500 ml. The results showed a dilatant behavior of the culture medium and pseudo-plastic behavior of cell cultures. This last behavior increases with cell concentration and size of the cell aggregates. Rheograms for all cell concentrations of A. indica, were significantly different from the other two species. Culture conditions like shaker orbit diameters and flask volumes were recommended in order to favor an adequate cell growth and mass transfer in plant cell cultures. (C) 2016 Elsevier B.V. All rights reserved.