Phylogenomic insights and recircumscription of the perennial endemic North American clade of Apiaceae (Apioideae, Selineae)

With ca. 200 morphologically variable species placed in 20 putative genera within the tribe Selineae of subfamily Apioideae, the Perennial Endemic North American (PENA) clade of Apiaceae forms the second‐largest plant radiation entirely endemic to North America, yet, elucidating evolutionary relationships for this intractable plant lineage has been challenging. The objectives of this study are to elucidate the monophyly of the PENA clade and assess phylogenetic relationships to other clades in Selineae, contributing to a refined understanding of relationships. By analyzing a robust sample set, including ingroup and outgroup taxa, we employ high‐throughput sequencing technologies to capture a wide array of nuclear DNA sequences using the Angiosperms353 baits. Our bioinformatics pipeline, incorporating both HybPiper and HybPhaser workflows, facilitated the recovery and analysis of targeted sequences, ensuring high‐quality data for maximum likelihood and multispecies pseudo‐coalescent phylogenetic reconstructions. Our phylogenetic analyses do not recover a monophyletic PENA that includes all genera presumed to be part of this clade. Our results prompted the realignment of genera to include in the PENA clade. Genera that occur primarily in eastern North America are moved out of PENA. We also resolve, for the first time, the placement of the genus Eurytaenia within Apiaceae. This study contributes to a deeper understanding of the phylogenetic relationships within a taxonomically complex group of western North American Apiaceae, paving the way for broader insights into plant diversity and evolution in this botanically complex region.