Stable hexagonal phases have been identified in the three monodisperse long n-alkanes C390H782, C294H590 and C246H494 at pressures similar to0.5 GPa and above. Their isobaric temperature range of stability widens with increasing pressure but decreases for shorter molecular lengths. Crystallization of hexagonal phases from the melt, often under metastable conditions and below the triple point, gives a characteristic morphology distinct from direct crystallization of the orthorhombic phase, as found for polyethylene. The data extend the known stability range of this two-dimensionally ordered phase to shorter molecules and complement previous work on polyethylene and short alkanes.