Benjamin Ajayi, Dr. Sunday Adeniran, Prof. Akeem Kadiri, Corresponding author: aderemibenjamin@gmail.com ABSTRACTS Morphological characters of seedlings were studied for 50 populations of Lageneria siceraria, the size, shape and indumentum of juvenile was used as taxonomic identification. The leaf showed heteroblastic changes with eophyll serving as interface for cotyledon and metaphyll for morphological traits. The phenotypic responses varied from one area of growth to the other which confers a good degree of taxonomic importance on seedling character of Lageneria siceraria. Adult plants showed vegetative and reproductive qualitative features that were analogous while quantitative characteristics varied among populations. Phenotypic stability level was 90-100% for plant height and inflorescence length whereas it was 10-45% for leaf size and petiole length. Generic grouping of the species would be adequate, based on similarities in seedling traits. Plant taxonomists can employ the approach in proffering solution to taxonomic intricacies and weed scientists will recognize the plants in the juvenile stage.