New Genus<i> Lobidiscus</i> and New Combinations of Genera of <i>Moutan</i>, <i>Liquidambar </i>and<i> Hamamelis</i> (Hamamelidales)

Abstract

Hamamelidales Griseb. (1854) order serves as a foundational group and plays a significant role in the research of evolutionary systematics of the class Rosopsida Batsch (1802) of Fructophyta D. L. Fu & H. Fu (2018). To address the ambiguities surrounding the circumscription of certain genera within this order, such as <i>Paeonia</i> L. (1753), <i>Liquidambar</i> L. (1753), and<i> Hamamelis</i> L. (1753), relevant chloroplast complete genome sequences from the NCBI database were retrieved, and evolutionary analyses were conducted on these sequences in this study. Notably,<i> Lobidiscus </i>D. L. Fu, gen. nov., a new genus endemic to America characterized by its distinctly lobed floral discs, has been separated from <i>Paeonia</i> L. belonging to Paeoniaceae (Bercht. & J. Presl) Rudolphi, nom. cons. (1830), and <i>Lobidiscus</i> <i>californicus</i> (Nutt.) D. L. Fu is designated as its type species. This new genus derives from <i>Moutan</i> Rchb. (1827), rather than <i>Paeonia</i> L., given that a maximum PHS value of 0.837 were observed between <i>Lobidiscus</i> <i>brownii</i> (Hook.) D. L. Fu and <i>Moutan</i> <i>delavayi </i>(Franch.) D. L. Fu based on CPCG evolutionary analyses. Meanwhile, the application of the minimum criterion PHS ≤ 0.928 (intergeneric, CPCG) for genus classification of Fructophyta D. L. Fu & H. Fu, has led to confirmation of two synonyms for <i>Liquidambar</i> L.: <i>Altingia</i> Noronha and <i>Semiliquidambar</i> H. T. Chang; additionally, three current synonyms for <i>Hamamelis</i> L., including <i>Distylium</i> Siebold & Zucc., <i>Parrotia</i> C. A. Mey., and <i>Sycopsis</i> Oliv., have been scientifically identified. In total, 13 novel family names like Liquidambaraceae D. L. Fu, Dianthaceae D. L. Fu, Diospyraceae D. L. Fu and Ilecaceae D. L. Fu have been established, along with two new specific epithets,<i> Hamamelis</i> <i>hubeiensis</i> D. L. Fu and<i> Hamamelis</i> <i>grandifolia </i>D. L. Fu, and 39 newly valid combinations involving <i>Hamamelis</i> L., <i>Liquidambar</i> L., <i>Lobidiscus </i>D. L. Fu, and<i> Moutan</i> Rchb. also been published, such as<i> Hamamelis</i> <i>annamica</i> (Gagnep.) D. L. Fu,<i> Liquidambar cambodiana </i>(Lecomte) D. L. Fu,<i> Lobidiscus</i> <i>brownii</i> (Hook.) D. L. Fu,<i> </i>and<i> Moutan</i> <i>suffruticosus</i> (Andrews) D. L. Fu. These contributions will effectively clarify taxonomic nomenclature confusions in a scientific manner while establishing a robust foundation for further research into the evolutionary systems within the order Hamamelidales Griseb.