Taxonomic complexity in the parasitic plant genus Cistanche : Evidence from phylogenomics

Abstract “Desert hyacinths” (genus Cistanche ) are striking parasitic plants of historical and cultural importance that include species traded widely for herbal medicine. Despite the need for robust taxonomy, the application of names in the genus remains confused. We present a phylogenomic framework for Cistanche informed by wide sampling and close examination of living material in the field. Our work recovered broadly geographically defined clades consistent with previous studies. However, the inclusion of living material from previously unsampled areas revealed the presence of co‐occurring morphologically similar yet genetically distinct lineages. We show that the current application of numerous names does not reflect evolutionary relatedness in the genus Cistanche , hindering research and conservation in this important group. Our work calls into question even data‐rich approaches in resolving the most taxonomically difficult plant genera.