Abstract
Chloranthus flavus was described as a new species in the recent past only based on morphological comparison, which was assumed to be related and compared to C. nervosus. In the present study, based on extensive investigations and observations of the wild and transplanted plants in combination with molecular phylogenetic studies, we found: C. flavus has wider distribution range, but is still fully embedded within that of the widespread C. nervosus and they even coexist in some populations; they have same phenology and furthermore, there are not any disjunct morphological characters that can be observed to separate them, even for the assumed most striking diagnostic trait of stamen (connective) color, which varies more or less continuously; moreover, molecular phylogenetic analyses based on population samples and both plastid and nuclear sequences indicated that the individuals of typical C. flavus are fully nested within and interdispersed with C. nervosus. All these prove that C. flavus is a synonym of C. nervosus and should be combined.
References
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Capella-Gutiérrez, S., Silla-Martínez, J.M. & Gabaldón, T. (2009) trimAl: a tool for automated alignment trimming in large-scale phylogenetic analyses. <em>Bioinformatics</em> 25: 1972–1973. https://doi.org/10.1093/bioinformatics/btp348</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Collett, H. & Hemsley, W.B. (1889) On a collection of plants from Upper Burma and the Shan States. <em>The Journal of the Linnean Society, Botany</em> 28 (190): 118.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Doyle, J.J. & Doyle, J.L. (1987) A rapid DNA isolation procedure for small quantities of fresh leaf tissue. <em>Phytochemical Bulletin</em> 19: 11–15.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Edgar, R.C. (2004) MUSCLE: multiple sequence alignment with high accuracy and high throughput. <em>Nucleic Acids Research</em> 32: 1792–1797. https://doi.org/10.1093/nar/gkh340</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Gray, A. (1859) Diagnostic characters of new species of phænogamous plants, collected in Japan by Charles Wright, botanist of the US North Pacific exploring expedition. With observations upon the relations of the Japanese flora to that of North America, and of other parts of the northern temperate zone. <em>Memoirs of the American Academy of Arts and Science</em>s 6: 377–452. https://doi.org/10.2307/25057953</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Handel-Mazzetti, H.R.E. (1929) Chloranthaceae. <em>In</em>: Handel-Mazzetti, H.R.E. & Brotherus, V.F. (Eds.) <em>Symbolae sinicae,</em> vol. 7. Julius Springer, Wien. pp. 156–157.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Jin, J.J., Yu, W.B., Yang, J.B., Song, Y., DePamphilis, C.W., Yi, T.S. & Li, D.Z. (2020) GetOrganelle: a fast and versatile toolkit for accurate de novo assembly of organelle genomes. <em>Genome Biology</em> 21: 1–31. https://doi.org/10.1186/s13059-020-02154-5</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Kalyaanamoorthy, S., Minh, B.Q., Wong, T.K., von Haeseler, A. & Jermiin, L.S. (2017) ModelFinder: fast model selection for accurate phylogenetic estimates. <em>Nature Methods</em> 14: 587–589. https://doi.org/10.1038/nmeth.4285</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Kong, H.Z. (2000a) Karyotypes of <em>Sarcandra</em> Gardn. and <em>Chloranthus </em>Swartz (Chloranthaceae) from China. <em>Botanical Journal of the Linnean Society</em> 133: 327–342. https://doi.org/10.1111/j.1095-8339.2000.tb01549.x</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Kong, H.Z. (2000b) <em>Systematics of the Genus Chlorantus Swartz (Chloranthaceae). Ph.D. Dissertation</em>. Beijing: Institute of Botany, Chinese Academy of Sciences. https://ir.ibcas.ac.cn/handle/2S10CLM1/13986</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Kong, H.Z. (2001) Comparative morphology of leaf epidermis in the Chloranthaceae. <em>Botanical Journal of the Linnean Society</em> 136: 279–294. https://doi.org/10.1111/j.1095-8339.2001.tb00573.x</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Kong, H.Z., Chen, Z.D. & Lu, A.M. (2002a) Phylogeny of <em>Chloranthus</em> (Chloranthaceae) based on nuclear ribosomal ITS and plastid <em>trnL-F</em> sequence data. <em>American Journal of Botany</em> 89: 940–946. https://doi.org/10.3732/ajb.89.6.940</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Kong, H.Z., Lu, A.M. & Endress, P.K. (2002b) Floral organogenesis of <em>Chloranthus sessilifolius</em>, with special emphasis on the morphological nature of the androecium of <em>Chloranthus</em> (Chloranthaceae). <em>Plant Systematics and Evolution</em> 232: 181–188. https://doi.org/10.1007/s006060200041</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Liu, D.T., Cai, L. & Chen, G. (2019) <em>Chloranthus flavus</em> (Chloranthaceae), a new species from Guangxi, China. <em>Phytotaxa</em> 391: 273–276. https://doi.org/10.11646/phytotaxa.391.4.6</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Liu, T.S. (1996) Chloranthaceae. <em>In</em>: Huang, T.C. (Ed.) <em>Flora of Taiwan, 2nd ed</em>. Editorial Committee of the Flora of Taiwan, Taipei. pp. 632–635.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Lu, Y.B., Jiang, Y.L., Qin, X.M. & Zhang, Q. (2020) Morphological diversity and geographical distribution of<em> Chloranthus</em> in China. <em>Guihaia</em> 40: 31–43. https://doi.org/10.11931/guihaia.gxzw201812011</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Makino, T. (1902) Observation on the Flora of Japan. <em>The Botanical Magazine</em> 16: 180.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Nguyen, L.T., Schmidt, H.A., Von Haeseler, A. & Minh, B.Q. (2015) IQ-TREE: a fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. <em>Molecular Biology and Evolution </em>32: 268–274. https://doi.org/10.1093/molbev/msu300</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Oliver, D. (1887) <em>Chloranthus angustifolius</em>, Oliv. Chloranthaceae. <em>In</em>: Hooker, W.J. (Ed.) <em>Hooker’s Icones Plantarum; or figures, with brief descriptive characters and remarks of new or rare plants. </em>Longman, London. 1580 pp.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Pei, C. & Shan, R.H. (1938) A study of Chinese <em>Chloranthus</em>. <em>Contributions from the Biological Laboratory of the Science Society of China: Botanical Series </em>10: 207–212.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Ronquist, F., Teslenko, M., Van Der Mark, P., Ayres, D.L., Darling, A., Höhna, S., Larget, B., Liu, L., Suchard, M.A. & Huelsenbeck, J.P. (2012) MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. <em>Systematic Biology</em> 61: 539–542. https://doi.org/10.1093/sysbio/sys029</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Siebold, P.F.von (1829) Einige wrote über den Zustand der Botanik auf Iapan in einem Schreiben an den Praesidenten der Akademie: nebst einer Monographie der Gattung Hydrangea und einigen Proben japanischer Litteratur über die Kräuterkunde. <em>Nova acta physico-medica Academiae Caesareae Leopoldino-Carolinae Naturae Curiosum</em> 14 (2): 671–696.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Solms-Laub, H.M.C.L.F. (1869) Chloranthaceae. <em>In</em>: Candolle, A.L.P.P. (Ed.) <em>Prodromus sytematis naturalis regni vegetabilis. </em>Sumptibus victoris Masson et Filii, Parisiis. pp. 472–485.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Swartz, O. (1787) <em>Chloranthus</em>, a new genus of plants, described by Olof Swartz, M. D. communicated by Sir Joseph Banks, Bart. P. R. S. <em>Philosophical Transactions of the Royal Society of London </em>77: 359–362. https://doi.org/10.1098/rstl.1787.0035</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Thunberg, C.P. (1784) <em>Flora Iaponica Sistens Plantas Insularum Iaponicarum</em>. In Bibliopolio I.G. Mülleriano, Lipsiae. 65 pp.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Verdcourt, B. (1992) Chloranthaceae. <em>In</em>: Smitinand, T. & Larsen, K. (Eds.) <em>Flora of Thailand</em>. Chutima Press, Bangkok, Thailand. pp. 424–430.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Wu, K.F. (1982) Chloranthaceae. <em>In</em>: Tseng, Y.C. (Ed.) <em>Flora Reipublicae Popularis Sinicae</em>, vol. 20 (1). Science Press, Beijing. pp. 77–95.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Xia, N.H. & Jérémie, J. (1999) Chloranthaceae Blume. <em>In</em>: Wu, Z.Y., Raven, P.H. & Hong, D.Y. (Eds.) <em>Flora of China</em>, vol. 4<em>. </em>Science Press, Beijing, China; Missouri Botanical Garden, St. Louis. pp. 132–138.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Ye, J., McGinnis, S. & Madden, T.L. (2006) BLAST: improvements for better sequence analysis. <em>Nucleic Acids Research</em> 34 (suppl_2): W6–W9.</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Zhang, Q., Antonelli, A., Feild, T.S. & Kong, H.Z. (2011) Revisiting taxonomy, morphological evolution, and fossil calibration strategies in Chloranthaceae. <em>Journal of Systematics and Evolution</em> 49: 315–329. https://doi.org/10.1111/j.1759-6831.2011.00129.x</span></span></span></p>
<p align="justify"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: small;">Zhang, Q., Feild, T.S. & Antonelli, A. (2015) Assessing the impact of phylogenetic incongruence on taxonomy, floral evolution, biogeographical history, and phylogenetic diversity. <em>American Journal of Botany</em> 102: 566–580. https://doi.org/10.3732/ajb.1400527</span></span></span></p>