Pitted morningglory is an adaptable species with an indigenous range encompassing the southern Midwest and southeast United States. In 2000 through 2002, 64 pitted morningglory accessions from 11 states were grown in Fayetteville, AR, to compare their morphology in a common environment to document potential morphological variation and to determine whether variation proves the existence of pitted morningglory morphological ecotypes. Accessions were evaluated for leaf size and vine length 8 wk after emergence (WAE), date of flower initiation, flower color, leaf pubescence 12 WAE, capsule and sepal pubescence, sepal length and width, plant weight, and seed number at physiological maturity. Morphological variables were standardized and analyzed with cluster analysis to differentiate the morphological variation among accessions. Documented variation was best described by eight clusters. Four clusters distinguished themselves morphologically. Accessions within these distinct clusters were originally from Arkansas, Delaware, Kentucky, Louisiana, Mississippi, and Missouri and were documented with leaf size, vine length, and day of flower initiation generally increasing with decreasing latitude. The other four clusters were nondistinct because most variables differed very little, but characteristics such as capsule pubescence separated these clusters. Accessions within these nondistinct clusters originated from Arkansas, Georgia, Louisiana, North Carolina, Oklahoma, and Tennessee. Leaf shapes of arrow, heart, an arrow and heart mixture, and heart with pointed projections and white or purple flower colors were documented. Documented differences indicate the existence of pitted morningglory morphological ecotypes.