This paper reports on the creation of a unique form of single crystalline two-dimensional (2-D) copper microdendritic plates and proposes a new crystal growth mechanism in an aqueous environment. The crystals are formed via reduction of CuSO4 with starch in aqueous solution. The 2-D crystals are typically similar to 300 nm thick and similar to 50 mu m wide, and consist of rhombic petals of (1 1 1) planar orientation. The plates are found to nucleate at the centre in polyhedral shapes and grow outwards along zigzag growth paths along the <1 1 (2) over bar > directions. Formation of such a crystal morphology is attributed to three different growth controlling criteria. The formation of polyhedral crystalline nuclei is controlled by the Gibbs-Wulff theorem, driven by the need to minimize the total surface energy for nucleation; growth of the crystal to form a 2-D rosette morphology is controlled by the planar expansion kinetics of low surface energy crystallographic planes; the zigzag dendritic growth pattern is dictated by the Cu2+ concentration gradient at the crystal growth fronts in the solution. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.