Taxonomic note of Parnassia (Celastraceae) in China: a reassessment of Subsect. Xiphosandra

Abstract

P.brevistyla, P.delavayi and P.leptophylla. belong to Celastraceae, ParnassiaL.,Sect.NectarotrilobosDrude,Subsect.Xiphosandra (Franch.) Ku. Due to lack of material, the reliability of their taxonomic characteristics remained unknown and all three species have been retained. Following extensive field investigations, population sampling and examination of specimens, we determined that the previously used characteristics to distinguish these three species, i.e. the shape of basal leaves and the depth of staminode lobes, vary continuously within populations and should not be used to distinguish separate species. Therefore, P.brevistyla and P.leptophylla are hereby designated as synonyms of P.delavayi.

Reassessment of the Phylogeny and Systematics of Chinese Parnassia (Celastraceae): A Thorough Investigation Using Whole Plastomes and Nuclear Ribosomal DNA

“…Hence, P. brevistyla and P. leptophylla were designated as synonyms of P. delavayi. In this study, the results of phylogenetic relationships showed that individuals of these three species were nested within each other (Figure 2), supporting the taxonomic revision of Yu et al (2018).…”

“…Xiphosandra (P. brevistyla, P. delavayi, and P. leptophylla). Yu et al (2018) found that the continuous characteristics were mistakenly used in distinguishing these three species. Hence, P. brevistyla and P. leptophylla were designated as synonyms of P. delavayi.…”

“…The distribution of Parnassia species in the Pan-Himalayan region often overlaps, and considerable morphological variation may occur within the same species. Scholars often have a different understanding of taxonomic traits, which led to different opinions about the infrageneric classification of the genus, including different ranks as section and series (Drude, 1875;Franchet, 1897;Engler, 1930;Handel-Mazzetti, 1941;Ku, 1987;Wu, 2003Wu, , 2005Shu, 2017), and a plethora of taxonomic revisions (Turner and Veldkamp, 2001;Wu et al, 2004Wu et al, , 2008Wu et al, , 2009Shu andZhang, 2016, 2017;Wang et al, 2018;Yu et al, 2018;Ma et al, 2020;Dai et al, 2021). However, most of these investigations were based on morphological characters and need to be validated with molecular phylogenetic studies.…”

Taxonomic note on Parnassia (Celastraceae): the identity of P. nubicola

“…1). The variation of staminodes in P. mysorensis Heyne ex Wight et Arnott (1834: 35), P. wightiana, and P. delavayi Franchet (1896: 267) has been discussed, suggesting that the diagnostic value of staminodes could have been overestimated (Suksathan 2009;Wang et al 2018;Yu et al 2018).…”

Parnassia zhengyuana sp. nov. and P. simianshanensis sp. nov.: two new species of Parnassia (Celastraceae) from karst caves and Danxia landform in southwest China

“…Staminode shape, lobes and the number of leaves on stem are the most important taxonomic traits for the subordinate classification of Parnassia (Candolle 1824, Drude 1875, Engler 1898, Handel-Mazzetti 1941, Hooker 1879, Gu 1987, Gu and Hultgård 2001. However, in a recent study (Yu 2018), a reassessment of P. subsect. Xiphosandra (Franch.)…”