Abstract
Identifying Schismatoglottis plants (Araceae) can be challenging because many species look very similar and differ only in small morphological details. This study aimed to examine shape variation and morphological relationships among three Schismatoglottis morphotypes; lanceolate, oblique, and sagittate, collected from different localities in South Cotabato. A quantitative field-based approach was used. Twenty-seven healthy and fully developed plants were sampled. Their leaves, petioles, stems, and roots were photographed for analysis. Landmarks were digitized from the images, and shape data were standardized using Generalized Procrustes Analysis. Patterns of variation were then examined using Principal Component Analysis (PCA) and Canonical Variate Analysis (CVA). The PCA results showed a high degree of overlap among the morphotypes, which suggests that shape differences occur gradually rather than forming clearly separate groups. In contrast, CVA produced clearer distinctions among the morphotypes, with leaf shape contributing the most to variation. A morphology-based tree constructed from PCA scores revealed two main clusters that reflected overall shape similarity rather than organ type. These findings reveal that geometric morphometrics is useful for detecting subtle morphological differences and can support the differentiation of Schismatoglottis morphotypes in South Cotabato.