Purple nutsedge collections from 13 states within the continental United States and from 21 other locations around the world were studied to compare their reproduction and morphological characteristics. Differences occurred in the number of shoots produced from single tubers, the number of leaves per shoot, and the length and width of leaves. Differences were also found with respect to flowering, length of culms supporting the inflorescences, and number, length, and width of involucral bracts at the apex of the culms. Variations occurred in the flower parts, including the number and length of rachises and the length of rachillae and spikelets. There were differences in the growth patterns of the leaves, with some collections having leaves mostly erect and others having leaves lie more closely to the ground. The color of the leaves varied between light and dark green, and the color of the inflorescence varied between light and dark purplish-brown. Greater variation was found among plants from different locations around the world than from within the continental United States.