Cuphea, Sanvitalia and Zinnia germplasm collections are maintained by the North Central Regional Plant Introduction Station (NCRPIS), Ames, Iowa, as part of the National Plant Germplasm System of the United States. A cooperative project was established by the NCRPIS and the Botany Department of the Universidad Nacional Aut6noma de Mexico (UNAM), Mexico City, to organize a collecting trip for these genera. This report summarizes the reasons for, and initial products of, the resulting expedition.