This dataset was created for examining the spatial distribution of plant size in a natural plant population, and for understanding the processes which govern the same. A winter annual species, Myosotis stricta (formally known as Myosotis micrantha), was chosen for this purpose. Data collection was carried on the campus of Stony Brook University (Stony Brook, NY, USA) in May 1988, along a 700 cm x 20 cm transect. It was found that a size hierarchy existed in this plant population. Plants lacking immediate conspecific neighbors were larger than plants with one or more near neighbours, suggesting that competition from near neighbours depressed plant size. However, there was a strong positive spatial autocorrelation in plant size: large plants were associated with large neighbours and small ones with small neighbors. Plant size was also positively correlated with the combined biomass of near neighbors. Thus, the population formed a two-phase mosaic of patches of relatively large plants alternating with patches of smaller plants. These results were published in the paper titled Plant size and spatial pattern in a natural population of Myosotis micrantha (Wilson and Gurevitch, 1995).