Analysis was made of isoenzyme and morphological differences among three small adjacent stands of Pinus pungens Lamb, and progeny derived from the stands. Results indicated that although significant differences were observed in measured characteristics among stands, progeny derived from the stands did not differ significantly. Analysis of gene frequencies for two esterase phenotypes indicated all three stands arose from a single panmictic population. The results of the analysis might be explained by environmental effects on the characteristics measured in situ, by genetic drift or by natural selection.