Integration of leaf traits supports the current circumscription of Afgekia Craib. and Padbruggea Miq. (Fabaceae, Wisterieae)

Accurate delimitation of <i>Afgekia</i> and <i>Padbruggea</i>, two morphologically similar genera in the tribe Wisterieae (Fabaceae), has long posed challenges by overlapping vegetative traits, particularly in the case of <i>P. filipes</i>, which had been historically misclassified under <i>Afgekia</i>. This study aims to clarify their generic boundaries by integrating comparative analyses of leaf traits, including venation architecture, trichome morphology, epidermal and stomatal characteristics, and transverse anatomy. Microscopic and image-based assessments were conducted across populations of <i>A. mahidoliae</i>, <i>A. sericea</i>, <i>P. dasyphylla</i>, and <i>P. filipes</i>. Results revealed stable inter- and infrageneric differences in leaf venation patterns, accessory vascular bundle types, trichome diversity, stomatal distribution, and presence of idioblasts and calcium oxalate crystals. Notably, <i>P. filipes</i> displayed diagnostic anatomical features that aligned more closely with <i>Padbruggea</i>, supporting its recent transfer from <i>Afgekia</i> based on phylogenetic studies. Despite some environmental inconsistencies, the observed traits showed high species-level stability across populations, underscoring their taxonomic significance. This integrative anatomical approach lends support to the current circumscription of both genera and suggests the continued relevance of vegetative anatomy as a complementary line of evidence to molecular data, potentially aiding the refinement of taxonomic concepts within Fabaceae.