Taxonomic position of (Apiaceae): insights from molecular and morphological evidence.

Speciation arises from multifaceted factors, making phenotype-based classifications unreliable. Integrative taxonomy has advanced significant breakthroughs in taxonomically challenging groups like Apiaceae, which is characterized by highly convergent morphological traits across species. The genus (Apiaceae) has long presented persistent taxonomic uncertainties. While morphological similarities initially supported as sect. , phylogenetic studies consistently resolve within the tribe Echinophoreae, contrasting with (tribe Selineae). Integrated morphological and molecular analyses were conducted here to resolve this taxonomic conflict. Phylogenetic reconstructions based on nuclear ribosomal DNA and plastomes all supported that and formed a stable monophyletic group with and within Echinophoreae, separate from . Plastome comparisons across 14 taxa revealed structural conservation in , , , and , particularly in inverted-repeat and single-copy regions, distinct from that of other species. A unique inversion involving the , , and genes was detected in and but absent in and . Shared morphological characteristics, including glabrous stem bases, basally free bracteoles, and prominent calyx teeth, further support their affinity with . We therefore propose to recognize as a separate genus rather than as sect. and reclassifying and into it. In conclusion, this study not only revealed the phylogenetic position of the tribe Echinophoreae but also resolved the long-standing taxonomic controversy surrounding and .