Lamellar thicknesses, cross-hatching frequencies and growth rates have been compared for spherulites, transcrystalline layers and row structures formed from the melt in the cu (monoclinic) form of isotactic polypropylene. These three morphologies relate to point, surface and linear nucleation, respectively. The measured quantities are independent of the type of nucleation confirming that morphological statistics compiled from row structures are relevant to general conditions of melt crystallization. This independence also implies that the same supercooling must be effective for growth in the three cases notwithstanding the very different geometries of their crystal/melt interfaces and the consequent locations and concentrations of any fractionated molecular species. With no detectable depression of supercooling at the growth faces the conditions for cellulation to develop do not exist. Segregation of ’impurities’ can thus have no influence on the establishment of physical texture in this high crystallinity polymer.