Geometric Morphometrics of Pistillate Flowers in Astrocaryum sect. Huicungo (Arecaceae): Taxonomic Implications for the Peruvian Species

Corolla shape in 549 pistillate flowers from 11 Peruvian Astrocaryum species shows higher discriminatory power than calyx shape, and combining both perianth parts maximizes assignment accuracy.

• Why it matters: Traditional qualitative floral traits in Astrocaryum sect. Huicungo conflict with phylogenomic results, leaving species boundaries uncertain. Quantitative shape metrics are needed to test whether floral geometry can delimit taxa despite overlap.
• What they did: Landmark-based 2D geometric morphometrics (4 landmarks, 16 semilandmarks) quantified symmetric variation in calyx and corolla across 549 flowers from 11 Peruvian species, using PCA and CVA plus cross-validated classification. Mahalanobis distance clustering was also used to compare geometric groupings with traditional subsections.
• The result: Morphological variation is continuous with extensive phenotypic overlap, yet perianth geometry retains a diagnostic signal; clustering did not match traditional subsections, with Astrocaryum chonta and A. ulei diverging and A. carnosum, A. faranae, and A. huicungo sharing strong geometric similarity.

AI summary of the abstract · may contain errors · not medical advice · read the paper.