Achene Morphological Traits as Taxonomic Markers in Ranunculus (Ranunculeae—Ranunculaceae) in Pakistan

Ranunculus , the largest genus of Ranunculaceae, includes around 1750 species and is both geographically widespread and taxonomically challenging. In this study, achene morphological features of 20 species collected from the highlands of Pakistan were examined using light and scanning electron microscopy to evaluate their systematic value. A range of achene shapes was observed—obovoid, ovoid, globose, suborbicular, broadly elliptic, and others. Three main surface ornamentation patterns were recorded: rugose, rugose‐reticulate, and reticulate. Epidermal cells were predominantly irregular, with some rectangular‐chiseled or rectangular to polygonal forms. Anticlinal walls were typically slightly raised, occasionally raised or finely folded, while periclinal walls varied from concave and smooth to finely folded, pusticulate, or orbicular. Achene length ranged from 1.35 mm ( R. hirtellus ) to 5.0 mm ( R. muricatus ), width from 1.06 mm ( R. pensylvanicus ) to 3.06 mm ( R. muricatus ), and beak length from 0.5 mm ( R. diffusus ) to 2.25 mm ( R. muricatus ). These traits offered reliable diagnostic characters for resolving taxonomic ambiguity. UPGMA cluster analysis further supported the utility of achene morphology in species‐level differentiation and revealed correlations consistent with the observed morphological data.