The crystal structures and molecular dynamics of solution-grown and melt-grown polycrystalline samples of n-hexatriacontane have been investigated by employing NMR, DSC and X-ray powder diffraction techniques. All solution-grown samples have the same orthorhombic structure, while the melt-grown samples are mixtures of a monoclinic and two orthorhombic structures. Defect motions of chain ends between all-trans and defect orientations are present in all crystal modifications at room temperature, but defect orientations have significantly higher populations in the orthorhombic structure which occurs only in the melt-grown sample.