Although weak interactions such as van der Waals, hydrogen bonding, and aromatic interactions drive the formation of most organic molecular crystals, MOFs are 3Dpolymers that have moderate to strong metal-ligand coordination bonds. Adding to the complexity of the formation of such coordination-based crystals is that their growth also involves at least two components: an organic ligand with multiple coordination sites and a metal salt. Numerous crystalline MOFs have been engineered at the structural level to have high porosity, stability, and affinity for small molecules (e.g., water, carbon dioxide, and methane). Their design is already based on computational screening and high-throughput predictions. After decades of fundamental research, custom-made MOFs are available in large commercial volumes. However, much less is known about the origin of their crystal morphologies. The growth of MOFs with different morphologies without any additives is not straightforward. Altering the reaction temperature and the cooling rate is known to result in MOFs with different morphologies and properties. We report here the correlation between morphologies and the crystallographic symmetry of a series of MOFs as a function of the metal-to-ligand ratio, and the nature of the metal cations (Scheme 1). A diverse series of morphologies have been demonstrated, including double-decker flowers and dendritic structures, rounded and slightly faceted crystals, as well as hexagonal prisms. Some of these structures have a multidomain appearance but are single crystals. Regardless of the copper nitrate-to-ligand ratios, the morphological symmetry of the crystals formed is controlled by the crystal symmetry. However, at relatively low metal-to-ligand salt ratios, these crystal symmetries result in highly unusual crystal morphologies (= double-decker flowers). The excess of ligand is a modulator for the crystal morphology. Interestingly, the follow-up experiments revealed the formation of an intermediate structure having a "stellate" morphology with a medial seam. The separation of layers is the key to the formation of the complex double-decker flowers. In despite of the widely different crystal morphologies, the crystallographic structures are similar and contain several elements of chirality (coordination nodes and helical channels). The channels are accessible, as demonstrated by the inclusion of dyes. 44