Comparisons between crowded and uncrowded Kochia scoparia individuals demonstrate pronounced effects of competition on plant allometry as well as on the distributions of different aspects of size. Non-destructive measurements of height and stem diameter and, for a subset of the populations, the number and length of leaves and branches, were taken at three times, and the plants were harvested after the third measurement. The sequential measurements afforded the opportunity to obtain information of the effects of competition on allometric growth trajectories of individuals, as well as on static inter-individual allometric relationships.