Lappula duplicicarpa var. brevispinula C.J.Wang (Boraginaceae) is a synonym of L. macrantha based on morphological and molecular data

Upon examining the type specimens of Lappula duplicicarpa var. duplicicarpa and L. duplicicarpa var. brevispinula, significant morphological differences were observed between these two taxa, indicating that the classification of L. duplicicarpa var. brevispinula as a variety may not be warranted. In this study, we conducted a comprehensive morphological comparison of L. duplicicarpa var. duplicicarpa, L. duplicicarpa var. brevispinula, and L. macrantha, alongside reconstructing a phylogenetic tree based on complete chloroplast genome data. The analyses suggest that L. duplicicarpa var. brevispinula and L. duplicicarpa var. duplicicarpa differ significantly in the morphology of the calyx, corolla, and eremocarps, as well as in the micro-morphological traits of the eremocarp. Statistically significant discontinuities were also observed in the sizes of the corolla and eremocarps. Notably, the morphological characteristics of L. duplicicarpa var. brevispinula fall within the range of variation exhibited by L. macrantha. Furthermore, in the chloroplast phylogenetic tree, L. duplicicarpa var. brevispinula and L. macrantha are nested together, indicating a close relationship. Consequently, both morphological and molecular evidence supports the conclusion that L. duplicicarpa var. brevispinula and L. macrantha are conspecific.