$¢PhytoKeys PhytoKeys 253: 261-270 (2025) DOI: 10.3897/phytokeys.253.142516 Research Article Pternopetalum shunhuangensis (Apiaceae), a new species from Hunan, China Wei Zhou™, Zi-Lin Feng2®, Long-Ping Tang*®, Du Deng*®, Bao-cheng Wu™, Lei Wu2® 1 Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), Nanjing 210014, Jiangsu, China 2 College of Forestry, Central South University of Forestry and Technology, Changsha 410004, China 3 Hunan Dong’an Shunhuang Mountain National Nature Reserve, Yongzhou 425901, China 4 College of Life and Environmental Sciences, Hunan University of Arts and Science, Changde 415000, China Corresponding author: Lei Wu (wuleiibk@163.com) OPEN Qeceess Academic editor: Alexander Sennikov Received: 23 November 2024 Accepted: 12 February 2025 Published: 12 March 2025 Citation: Zhou W, Feng Z-L, Tang L-P Deng D, Wu B-c, Wu L (2025) Pternopetalum shunhuangensis (Apiaceae), a new species from Hunan, China. PhytoKeys 253: 261-270. https://doi.org/10.3897/ phytokeys.253.142516 Copyright: © Wei Zhou et al. This is an open access article distributed under terms of the Creative Commons Attribution License (Attribution 4.0 International - CC BY 4.0). Abstract Based on field investigations, morphological and molecular systematic studies, a new species, Pternopetalum shunhuangensis (Apiaceae) from Hunan Province, China is de- scribed. Diagnostic morphological characters, full description and a detailed illustration are provided. The differences between P shunhuangensis and morphologically similar species P. tanakae are presented and discussed. Since no population assessment of this species in its whole distribution area is made, it is best to assign a conservation status of ‘Data Deficient’ (DD) for this species. Key words: Apiaceae, China, new species, Pternopetalum Introduction Pternopetalum Franch. (Apiaceae), including ca. 25 species, is endemic to East Asia (Shan and Pu 1978; Pu 1985; Wu et al. 2006). Typical characteristics of this genus are petals saccate at base, umbellules with 2-5 flowers, and rays reflexed in fruit. In Wang's revision (Wang 2007), the shape of the underground part, leaf morphology, the position of umbels, and the characteristics of flowers and fruits are important traits for delimiting Pternopeta/lum species. With 23 species, 21 of which are endemic (Pu and Phillippe 2005), China is undoubtedly the center of diversity and endemism for Pternopetalum. Wang (2012) recognized only 15 species in the genus, while Pimenov (2017) consid- ered it the eighth largest genus of Apiaceae in China, comprising 21 species. After Wang's revision, three new species and one new combination of Pternope- talum were described from China (Tan et al. 2014, 2015; Zhong et al. 2018; Ye et al. 2020). Even the species P arunachalense Bhaumik & P. Satyanar. which was published by Indian scholars Bhaumik and Satyanarayana (2014) was found in Southern Xizang according to the officially claimed boundary. Species of Pternopetalum are mainly distributed in the southwest area of China, especially in Sichuan and Yunnan (Su and Sheh 2001). However, Hunan Province in Central China is also one of the concentrated distribution areas 261 Wei Zhou et al.: Pternopetalum shunhuangensis (Apiaceae), a new species from China of this genus. There are ten species of Pternopetalum in Hunan, making it the largest genus of Apiaceae in the province (Sun et al. 2010). During an arduous journey to the Hunan Dong’an Shunhuang Mountain Na- tional Nature Reserve in April 2024, we found an interesting population of Pterno- petalum with flowers and young fruits. The species possesses unusual cauline leaves that are homomorphic with the basal leaves, sometimes even larger. In July and October, we returned to the locality and collected specimens with ma- ture fruits. According to the characters of fruit, the species obviously belongs to P sect. Pteridophyllae Wolff due to its minute calyx teeth and filiform ribs, but the homomorphic basal and cauline leaves differentiate it from all the other species of the section. Its relatively small habit and distinct fruit characteristics, also dis- tinguish it from all the species in the other section, i.e., sect. Denterioideae Wolff. After thorough consultation of the relevant literature and herbarium inves- tigations, and comparison with morphologically similar species, we are confi- dent that this is a new species of Pternopetalum. Materials and methods Morphological observation Specimens were collected from Dong’an County in three field trips during April, July and October 2024. The habitat of the new species was investigated in the field. Descriptions are based on dried collections, except for flower colour. DNA extraction, amplification and sequencing We collected fresh green leaves of this new species from Hunan, China. Total genomic DNA was extracted from silica-dried leaves with a plant genomic DNA kit (Tiangen Biotech Co., Ltd., Beijing, China). We used the nuclear ribosomal DNA internal transcribed spacer (ITS) for phylogenetic analyses. The universal primers ITS4 and ITS5 (White et al. 1990) were used to amplify the nuclear ribo- somal ITS region. Amplification was undertaken using a volume of 25 ul with 20 ul Green Tag Mix (Novogene, China), 1.5 ul forward primer, 1.5 pl reverse primer, and 2 ul total DNA. The amplification of the ITS region was obtained by initial denaturation for 2 min at 98 °C, followed by 35 cycles of 10 s at 98 °C,15s at 52 °C, and 15 s at 72 °C, and then a final extension of 5 min at 72 °C. All PCR products were separated using a 1.5% (w/v) agarose TAE gel and sent to San- gon (Nanjing, China) for sequencing. Phylogenetic analysis To confirm the phylogenetic position of this species, 28 ITS belonging to 15 species with accession numbers were obtained from GenBank. A total of 29 taxa were sampled for phylogenetic analysis, including 27 taxa and 14 spe- cies from Pternopetalum. Two species Oenanthe hookeri C. B. Clarke and Sium suave Walter, served as outgroups. We used SeqMan7 (Burland 2000) to assemble ITS sequences. The sequenc- es were aligned using MAFFT v7.221 (Katoh and Standley 2013). The alignment was employed to reconstruct the phylogenetic tree using Maximum-Likelihood PhytoKeys 253: 261-270 (2025), DOI: 10.3897/phytokeys.253.142516 262 Wei Zhou et al.: Pternopetalum shunhuangensis (Apiaceae), a new species from China (ML) and Bayesian Inference (BI) methods. For ML analyses, the software RAx- ML v8.2.8 (Stamatakis 2014) was used to construct the phylogenetic trees with the GTR model and 1000 bootstrap (BS) replicates. Bayesian inference (BI) analyses were conducted by MrBayes version 3.2.7 (Ronquist et al. 2012) with the best-fit substitution model (GTR+G+l) determined by Modeltest v3.7 (Posada and Crandall 1998). Markov Chain Monte Carlo (MCMC) search was performed for 1 x 10° generations, sampling every 1000 generations. Results and discussion Molecular phylogenetic analyses based on the internal transcribed space (ITS) region showed that P shunhuangensis is sister to P tanakae (Franch. & Sav.) Hand.-Mazz. and P gracillimum (H. Wolff) Hand.-Mazz. (Fig. 4). Thus, both mor- phological and phylogenetic evidence suggested that P shunhuangensis is a distinct species of Pternopetalum. After examining of herbarium specimens, we found that two other collec- tions of the same species were collected in 1962 and 1984 respectively from Ziyun Mountain, which is part of the Shunhuang Mountain. However, they were misidentified as P heterophyllum Hand.-Mazz. and P filicinum (Franch.) Hand.- Mazz respectively. Both of the two species have already been treated as syn- onym of P. tanakae (Franch. & Sav.) Hand.-Mazz by Wang (2012). This treat- ment is widely accepted. The new species resembles P. tanakae in possessing the minute calyx teeth and filiform ribs, but differs from the latter by roots without tubercles at nodes, fewer basal leaves, cauline leaves and stems and elongate styles (Fig. 3F). In fact, the length of ultimate segments of the cauline leaves in the two species are distinctly different (3-5 mm in P shunhuangensis vs.10-25 mm in P. tanakae; Fig. 3D). As no population assessment has been conducted for this species in its en- tire range, it is best to assign a conservation status of ‘Data Deficient’ (DD) for this species (IUCN Standards and Petitions Committee 2022). Taxonomic treatment Pternopetalum shunhuangensis W.Zhou & L.Wu, sp. nov. urn:lsid:ipni.org:names:77358254-1 FIGS1=3 Type. CHINA * Hunan Province, Yongzhou City, Dong’an County, Hunan Dong’an Shunhuang Mountain National Nature Reserve, on rocks densely covered with moss in forests, at an altitude ca 1600 m a.s.I., 23 Apr. 2024, Lei WU, Yan-Jie Yang, Zi-Lin Feng SHS0007 (holotype NAS); 19 July 2024, Lei WU, D. Deng, Zi-Lin Feng SHS1749 (paratype CSFI). Etymology. The species epithet is derived from the type locality, Shunhuang Mountain. Its Chinese name is given as 32.33% [Pinyin: shun hudng nang ban gin]. Diagnosis. Pternopetalum shunhuangensis differs from P. tanakae (Franch. & Sav.) Hand.-Mazz. by its roots without tubercles at nodes, fewer basal leaves, un- elongated ultimate segments of cauline leaves, elongate styles and terminal um- bels. A more detailed comparison between the two species is presented in Table 1. PhytoKeys 253: 261-270 (2025), DOI: 10.3897/phytokeys.253.142516 763 Wei Zhou et al.: Pternopetalum shunhuangensis (Apiaceae), a new species from China Figure 1. Illustration of Pternopetalum shunhuangensis W. Zhou & L. Wu A habit B another type of basal leaf C umbel in fruit D flower with two petals removed to show stamens and stylopodium E umbel in flower F mericarps. (Drawn by B. S. Li). Plants 12-16 cm high. Taproot fusiform. Stem 1, erect, slender, unbranched, glabrous. Basal leaves 0-1(2), petiolate; petioles 3-5 cm; blade ovate-triangu- lar, 1.5-3 x 2.5-3 cm, ternate or ternate-2-pinnate; ultimate segments flabelli- form or diamond, 3-8 x 2—7 mm. Cauline leaves 1, ternate-2-pinnate, petioles 0.5-4 cm; 2-4.5 x 3-6 cm, ultimate segments flabelliform or diamond, 2-5 x 2-6 mm. Umbels 1-3 cm across in flower, to 5 cm in fruit; bracts absent; rays PhytoKeys 253: 261-270 (2025), DOI: 10.3897/phytokeys.253.142516 264 Wei Zhou et al.: Pternopetalum shunhuangensis (Apiaceae), a new species from China Figure 2. Pternopetalum shunhuangensis W. Zhou & L. Wu A microhabitat B habit C flowering plant D abaxial surface of cauline leaf E umbels in fruit F mature fruit G root. Scale bars: 2 cm (B); 1 cm (C-D, G); 2 mm (E-F). 6-20, 1.5-2.5 cm; bracteoles 2-3; umbellules 2-flowered; pedicels 0.2-1 mm long. Calyx teeth minute, or obsolete. Petals white, broad ovate, 1.5-1.8 x 1.2- 1.5 mm; stylopodium conic; styles elongate, erect, longer than the stylopodium; stylopodium plus style ca 0.8mm, styles ca. 0.5 mm. Fruit oblong ovoid, 2-2.5 x 1-1.5 mm; ribs filiform; vittae 1-2 in each furrow, 2 on commissure. PhytoKeys 253: 261-270 (2025), DOI: 10.3897/phytokeys.253.142516 765 Wei Zhou et al.: Pternopetalum shunhuangensis (Apiaceae), a new species from China eps HME ACF OR RAL AS top. iy (vse- ) 1994 Teste MsG.Pimenov z 9 y t G ea as ES ic | nt | (aT panieses jyBAdoo ) Pternopetalun heterophyllum Hand.-Mazz. Det. F.D. Pu Sept. 1992 WI XE od I He 8 I ay MEO Jil i] my POR sist ta iF oy te mae AW LEE y m ote4 ee a | Ez A aA ee Unibellterne Fh. parent. Pamopeetabion Jamahas , ond. PLANTAE SZECHUANENSE A 2a 29 30 26 27 25 15 16 17 18 19 20 21 22 23 fe ly BE 4 i 6 7 8 9 IO 0 re 2 S: 3 Wut > Plemopetatlm Linum CP) Hd es HENRY 600 Ho m | | | | MA | os . . a [Paar eneary nner ec saree get genre every apcegen acevo cases seacoast gangs acta gna oO a HERB. MUS. PARIS. HERB. MUS. PARIS. Af 4 Tees fg, Re ae a ‘_ TE Crem barnes Timea, "Mijyro rin Atl Paani” Hyper seorne Fiver. a O Parra Fronts firs Laas, Se ne ie : C Phernopetaluny tanakee (( Camh. 2 Sov. ) Hand Mhze ay Re le Dt Sitinak 1866-74. Figure 3. Type specimens of Pternopetalum shunhuangensis, P. heterophyllum, P. filicinum and P. tanakae. A holotype of P. shunhuangensis (NAS) B holotype of P. heterophyllum (E00265241) C isotype of P filicinum (P00432458) D holotype of P. tanakae (P00495952). ICH ANG, prov.de HUTEH (Chine). PhytoKeys 253: 261-270 (2025), DOI: 10.3897/phytokeys.253.142516 266 Wei Zhou et al.: Pternopetalum shunhuangensis (Apiaceae), a new species from China 0.586/26 0.979/68 P. tanakae KP940736 \P. tanakae KP940741 1/96 P. tanakae KP940742 P. tanakae KP940738 0887/40 P. tanakae KP940737 P. gracillimum KP940710 P. gracillimum KP940711 P. subalpinum KP940734 P. shunhuangensis 0.994/75 P. nudicaule KP940730 | P. nudicaule KP940731 P. davidii KP940699 P. bipinnatum KP940692 P. rosthornii KP940732 P. trichomanifolium KP940746 P. botrychioides KP940695 1/83 P. monophyllum KP940729 P. trichomanifolium KP940747 0.392/29 P. trichomanifolium KP940745 1/100 P. vulgare KP940752 P. vulgare KP940748 P. caespitosum KP940696 1/99 P. delavayi KP940708 0.570/75 P. delavayi MH117687 P. delavayi KP940704 P. delavayi KP940705 P. delavayi KP940706 1/100 | Oenanthe hookeri EU236182 | Sium suave OLA72973 0.997/72 | 0.999/84 0.752/32 1/98 Figure 4. Phylogenetic tree inferred from the nrDNA ITS sequences. Bayesian posterior probability values (PP) / Boot- strap support values (BS) are shown on the branches. Only branches with PP > 0.5 are shown. Table 1. Comparison of Pternopetalum shunhuangensis and P. tanakae. Morphological data for P tanakae are obtained from Pu and Phillippe (2005). Characters P. shunhuangensis P. tanakae Height (cm) 26 10-40 Root without tubercles at nodes with tubercles at nodes Stem 1, unbranched 1-2, 1-2 branched or unbranched. Basal leaves 0-2 2-4 Cauline leaves 1, ultimate segments flabelliform | 1-3, ultimate segments lanceolate or diamond or elongate-linear Position of umbels terminal lateral and terminal Number of flowers in z it=s3 each umbellule Style longer than stylopodium shorter than stylopodium Phenology. Pternopetalum shunhuangensis is flowering from April to May, and fruiting from June to July. Additional specimens examined. Pternopetalum shunhuangensis (paratypes): CHINA * Hunan Province: Xinning County, 21 Oct. 1962 Lin-Han Liu 15250 (NAS, WUK); Xinning County, Ziyun mountain, 9 Sep. 1984 Ziyunshan Team 307, 987 (PE). P. tanakae: JAPAN °* Silvis montis ignivomi, Fudsi Yama, Jun. 1874 Savatier 3436 (holotype P, image). PhytoKeys 253: 261-270 (2025), DOI: 10.3897/phytokeys.253.142516 267 Wei Zhou et al.: Pternopetalum shunhuangensis (Apiaceae), a new species from China P heterophyllum: CHINA * Hunan Province: Xinning County, Huping mountain, 10 Jul. 1987 Hupingshan Team 1378 (PE); Sichuan Province: Baoxing County, 7 Agu. 1936 Gui-ling Qu 3454 (holotype E, image). P filicinum: CHINA * Hubei Province: Ichang City, A. Henry 6600 (isotype P image). Acknowledgments We are grateful to Bi-Shan Li for the line drawing. We would like to thank Xiao- Wen Liao, Lu Zhu, Zheng-Ren Li and Jun-Yun Tang for their help with the collec- tion of materials in the field. Thanks are due to Dr. Jun Wen for her kind help with the sequence data of Pternopetalum and suggestions for improving the manuscript. Master's student Jun-Wen Zhu made contributions to this work. Our thanks also go to the curators of NAS, PE, WUK and P for allowing us to examine their specimens or specimen photos. Additional information Conflict of interest The authors have declared that no competing interests exist. Ethical statement No ethical statement was reported. Funding This work was supported by the National Natural Science Foundation of China (grant No. 32370220) and the Natural Science Foundation of Hunan (grant No. 2025JJ50122). Author contributions Wei Zhou: Writing - Original draft; Wei Zhou and Lei Wu: Writing — Review and Editing; Zi-Lin Feng and Bao-cheng Wu: Data Curation; Lei Wu, Long-Ping Tang and Du Deng: Investigation. Author ORCIDs Wei Zhou © https://orcid.org/0000-0003-1627-1529 Zi-Lin Feng © https://orcid.org/0009-0000-4283-5135 Long-Ping Tang © https://orcid.org/0009-0003-6590-1491 Du Deng ® https://orcid.org/0009-0000-5476-4098 Bao-cheng Wu © https://orcid.org/0009-0006-1719-3517 Lei Wu © https://orcid.org/0000-0003-1451-7855 Data availability All of the data that support the findings of this study are available in the main text or Supplementary Information. References Bhaumik M, Satyanarayana P (2014) Pternopetalum arunachalense sp. nov. (Apiaceae) from India. Nordic Journal of Botany 32(4): 471-473. https://doi.org/10.1111/j.1756- 1051.2013.00305.x PhytoKeys 253: 261-270 (2025), DOI: 10.3897/phytokeys.253.142516 268 Wei Zhou et al.: Pternopetalum shunhuangensis (Apiaceae), a new species from China Burland TG (2000) DNASTAR’s Lasergene sequence analysis software. 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Nordic Journal of Botany 36(4): e01549. https://doi.org/10.1111/njb.01549 Supplementary material 1 Supplementary data Authors: Wei Zhou, Zi-Lin Feng, Long-Ping Tang, Du Deng, Bao-cheng Wu, Lei Wu Data type: fasta Copyright notice: This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited. Link: https://doi.org/10.3897/phytokeys.253.142516.suppl1 PhytoKeys 253: 261-270 (2025), DOI: 10.3897/phytokeys.253.142516 270