The occurrence of structural variants during epitaxial growth is examined using two-dimensional symmetry. The modeling of the materials includes equilibrium defect structures and reconstructions in addition to epitaxial strain and flaws. Specific results are presented for single and multi-terrace systems and for miscut substrates. Analytical results for planes on which variants nucleate in equal proportions are obtained simply, from two-dimensional symmetry arguments. These are used to discuss ways to inhibit the growth of unwanted variants.