Research Article |
Corresponding author: Yong-Hua Zhang ( zhangyhua@wzu.edu.cn ) Corresponding author: Pan Li ( panli_zju@126.com ) Academic editor: Alan Paton
© 2022 Xin-Jie Jin, Yue Huang, Yu-Kun Wei, Qing Ma, Lu-Xian Liu, Zhi-Xi Fu, Gui-Fang Wu, Yong-Hua Zhang, Pan Li.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Jin X-J, Huang Y, Wei Y-K, Ma Q, Liu L-X, Fu Z-X, Wu G-F, Zhang Y-H, Li P (2022) Elsholtzia zhongyangii (Lamiaceae), a new species from Sichuan, China. PhytoKeys 193: 77-88. https://doi.org/10.3897/phytokeys.193.80327
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Elsholtzia zhongyangii (Lamiaceae), a new species from Sichuan Province, China, is described and illustrated. The new species is morphologically similar to E. feddei f. feddei, but it can be easily distinguished from E. feddei f. feddei by smaller corolla (3.2–3.5 mm vs. 4.5–5.3 mm), bract indumentum (glabrous, except margin ciliate vs. villous, especially on veins abaxially, glabrous adaxially) and bract stalked (ca. 1.2 mm vs. sessile). Phylogenetic analyses, based on two nuclear ribosomal (ETS, ITS) and five plastid (rbcL, matK, trnL-F, ycf1, ycf1-rps15) regions, confirmed that the new species formed a monophyletic clade with robust support. The new species is currently known from western Sichuan.
Aromatic plant, Elsholtzieae, phylogeny, traditional medicinal herbs, taxonomy
Elsholtzia Willdenow (Lamiaceae) is a member of the tribe Elsholtzieae (
During our botanical expedition to Yajiang County, Sichuan Province in September 2012, we discovered an unknown species of Elsholtzia. It is similar to Elsholtzia feddei f. feddei in calyx (villous, with two long and three short teeth with spinescent apices) and leaf apices acute, but differs from the latter by its smaller corolla (3.2–3.5 mm vs. 4.5–5.3 mm), bract glabrous, with a ciliate margin (vs. villous, especially on veins abaxially, glabrous adaxially) and bract stalked (ca. 1.2 mm vs. sessile). After carefully checking specimens and literature, together with evidence from molecular phylogenetic analyses, based on combined nrDNA (ETS, ITS) and combined ptDNA (rbcL, matK, trnL-F, ycf1, ycf1-rps15) datasets, we demonstrated that it is, indeed, a new species which is described and illustrated here.
The morphological characters were examined, based on the living plants and specimens. Elsholtzia specimens, collected from Sichuan, were checked in the Herbaria of CDBI, CDCM, CQNW, HITBC, HNWP, HZU, IBK, IBSC, KUN, NAS, PE, SM, SZ, TIE, WCSBG, WUK and WZUH (acronyms as in
A total of 48 individuals of E. zhongyangii were collected from Yajiang County, Sichuan Province, China from September 2012 to December 2021 (Fig.
Two samples of the new species were sequenced using the genome skimming approach, then 14 sequences [each sample has two nrDNA (ETS, ITS) and five ptDNA (rbcL, matK, trnL-F, ycf1, ycf1-rps15) sequences as listed in Suppl. material
Maximum Likelihood (ML) analyses were performed in IQtree v.1.6.12 (
Incongruences amongst different datasets (combined ptDNA dataset, combined nrDNA dataset) were explored through visual comparison of tree topologies and support values. Hard incongruence was defined as BS ≥ 80% and/or PP ≥ 0.95 (
Detailed morphological comparisons between the new species and four other sympatric or morphologically similar taxa are summarised in Table
Morphological comparisons among Elsholtzia zhongyangii and its close relatives.
Species Characters | Elsholtzia zhongyangii | E. splendens | E. feddei f. robusta | E. feddei f. feddei | E. ciliata | E. souliei | |
---|---|---|---|---|---|---|---|
Plant | Tall | 10–45 cm | 30–50 cm | 20–30 cm | 10–20 cm | 30–50 cm | < 10 cm |
Inflorescence | Bract villous | Glabrous | Glabrous | Densely villous abaxially, glabrous adaxially | Villous, especially on veins abaxially, glabrous adaxially | Subglabrous abaxially, glabrous adaxially | Villous abaxially, glabrous adaxially |
Flower | Corolla size | 3.2–3.5 mm | 6–7 mm | 4.6–5.0 mm | 4.5–5.3 mm | ca. 4.5 mm | ca. 6 mm |
Calyx villous | White villous outside | White hispidulous | White villous outside | White villous outside | Pilose | White villous | |
Calyx apices | Apex spinescent | Caudate | Apex spinescent | Apex spinescent | Apex spinescent | Apex spinescent | |
Calyx length | Two long and three short | Subequal | Two long and three short | Two long and three short | Two long and three short | Two long and three short | |
Bract | Stalked, ca. 1.2 mm | Sessile | Sessile | Sessile | Sessile | Sessile | |
Leaves | Apices | Acute | Acuminate | Acute | Acute | Acuminate | Acuminate |
Margin | Obtuse serrate | Remotely serrate | Obtuse serrate | Obtuse serrate | Denticle | Obtuse serrate | |
Blade | Villous | Sparsely fine pilose | Villous | Villous | Sparsely minutely hispid | Villous |
The aligned sequences of nrDNA (ETS, ITS) and ptDNA (rbcL, matK, trnL-F, ycf1, ycf1-rps15) for phylogenetic analyses were 1,023 bp and 7,010 bp in length, respectively. Elsholtzia zhongyangii was recovered as a monophyletic clade in the two resulting phylogenetic trees obtained in this study (PP: 100, BS: 1, Fig.
Visual comparison of the resulting topologies, based on supporting values, revealed well-supported discrepancies for the combined nrDNA (ITS, ETS) and combined ptDNA (rbcL, matK, trnL-F, ycf1, ycf1-rps15) datasets. Two trees received strong support, but with conflicting tree topologies. The E. feddei-E. ciliata clade was sister to E. strobilifera in the ptDNA tree (PP: 99, BS: 1, Fig.
China. Sichuan: Yajiang County, Agakeyong, 30°2.54'N, 100°15.01'E, 3237 m a.s.l., 18 Sep 2018, Pan Li LP185940 (holotype, ZM; isotypes CSH, CDBI, HZU, KUN, PE, SZ, WZUH). (Fig.
Elsholtzia zhongyangii sp. nov. A blooming plant B front view of inflorescence C dorsal view of inflorescence D side view of inflorescence E cyme F bract G flower H side view of flower I front part of flower J villous outside corolla K dissected corolla L pilose annulate inside M ovary 4-cleft, 1 nectary rises on the edge of the ovary N outside of calyx O nutlet (with mucilage) P adaxial surface of leaf Q abaxial surface of leaf. Photos by Xin-Jie Jin & Pan Li.
Elsholtzia zhongyangii is most similar to E. feddei f. feddei morphologically in having calyx villous, spinescent calyx apex, two long and three short calyces and acute leaf apices, but differs from the latter by its smaller corolla (3.2–3.5 mm vs. 4.5–5.3 mm), bract stalked (ca. 1.2 mm vs. sessile) and bract glabrous, except margin ciliate (vs. villous, especially on veins abaxially, glabrous adaxially).
Annual herbs, erect. Stems 10–45 cm tall, tawny purple; pilose or pilulose, multi-branched above base, branch apex with inflorescence, internode 0.5–4.8 cm long. Leaves ovate triangular, ovate oblong to oblong lanceolate or lanceolate, 0.7–3.6 cm long and 0.3–1.7 cm wide, apex acute, base broadly or narrowly cuneate, extending to petiole, with dense glandular. Leaves villous adaxially, villous especially on veins abaxially. Leaf margin serrate, obtuse, occasionally acute, serrate margin usually purple. Inflorescence a terminal spike, secund, ca. 0.9–7.9 cm, flowers 8–14 at each node of the inflorescence (a pair of cymes); bracts subcircular to broadly ovate, ca. 1.2–3.2 × 1.1–4.5 mm, caudate cuspidate, apex ca. 0.7–2.1 mm, glabrous, except margin ciliate, with dense glandular, dark magenta at maturity, bract stalked, ca. 1.2 mm. Pedicel ca. 2 mm long, enlarged at apex, glabrous. Calyx ca. 2.0–3.2 mm, teeth 5, teeth triangular, two long and three short, apex spinescent,white hirsute, margin ciliate. Corolla deep purple, 3.2–3.5 mm, slightly incurved, narrowly funnel-shaped, with hairs transparent and purple interlaced, villous outside, pilose annulate inside, the base of the corolla tube is about 0.5 mm wide, widening upwards, throat about 1.2 mm wide, upper lip emarginated; middle lobe of lower lip semicircular, lateral lobes subcircular, shorter than middle lobe. Stamens 4, protruding from corolla, the anterior longer than the posterior, filaments are glabrous, anthers purple-black. Style longer than stamens at maturity, exserted, 2-cleft, with lobe equal, linear. Ovary 4-cleft; disc persistent, 1 nectary rises on the edge of the ovary. Nutlets 4, brown, oblong, ca. 1.1 mm long, 0.7 mm in diameter, surface becoming mucilaginous when wetted.
Flowering and fruiting from September to December.
Zhong-yang-xiang-ru (钟扬香薷).
The specific epithet is named in memory of Prof. Yang Zhong, a Chinese botanist who was dedicated to botanical research and education in Xizang (Tibet), China.
– Endemic to China, Sichuan Province, Yajiang County (Wolongsi, Weidi, Agakeyong, Jialulongba and Zhusang), Litang County (Wenquan), Ganzi County, Dege County (Ezhi), Luhuo County (Zhuwo) and Batang County. Growing in grassland on mountain slopes or even along the road, at an elevation of 3000–4000 m.
The known localities of Elsholtzia zhongyangii are not in protected areas. During our field surveys between September 2012 and December 2021, populations in Wolongsi, Weidi, Agakeyong, Jialulongba and Zhusang of Yajiang County were found. Specimen records show that it also occurs in Litang County (Wenquan), Ganzi County, Dege County (Ezhi), Luhuo County (Zhuwo) and Batang County. Taking into consideration that it was distributed along the roadsides like weeds, we believe that it should have a much wider distribution than what is now known. Due to its wide distribution range and large population size, Elsholtzia zhongyangii is here recommended as Least Concern (LC), according to the IUCN Categories (
China. Sichuan: Yajiang County, Wolongsi, 30°2.54'N, 101°15.08'E, 3293 m a.s.l., 26 August 2015, Pan Li & Xinglv Xie LP150689 (PE, KUN, WZUH); Yajiang County, Weidi, 30°3.13'N, 101°12.66'E, 3028 m a.s.l., 18 September 2018, Pan Li LP185942 (PE, WZUH); Yajiang County, Jialulongba, 30°2.94'N, 101°18.42'E, 3760 m a.s.l., 26 August 2015, Pan Li & Xinglv Xie LP150686 (PE, KUN, CDBI, SZ, CSH, WZUH); Yajiang County, Zhusang, 19 September 2012, Pan Li PNLI20120191 (WZUH); Litang County, Wenquan, 4000 m a.s.l., 11 September 1974, Y.Q. He & H.J. Wang 8281 (WUK); Ganzi County, 10 September 1951, W.G. Hu 13099 (WUK); Dege County, Ezhi, 1900 m a.s.l., 31 August 1979, Dege team 0685 (SM); Luhuo County, Zhuwo, 3700 m a.s.l., 2 August 1974, Sichuan vegetation team 07693 (CDBI); Batang County, 3100 m a.s.l., 2 September 1973, Sichuan vegetation team 3971 (CDBI).
Elsholtzia zhongyangii usually grows together with E. ciliata or other Elsholtzia species in grassland on mountainsides or even along roadsides, thus it must have been overlooked previously. We found that the plant is fragrant with dense glands. This species may be suitable as an aromatic plant, and thus it has the potential for development and application values.
There is one other Elsholtzia species with small corolla recorded in Sichuan, i.e. E. souliei. However, E. souliei is distantly related to the new species in the phylogenetic tree (Fig.
Within the genus Elsholtzia, the taxonomy of the E. splendens-E. ciliata clade is the most problematic. For example, in the Flora Reipublicae Popularis Sinicae,
This research is supported by the National Natural Science Foundation of China (Grant Nos. 31800309, 31800187), The Natural Science Foundation of Zhejiang Province (Grant No. LY21C030002), the Open Fund of Shanghai Key Laboratory of Plant Functional Genomics and Resources (Grant No. PFGR202104) and The Scientific Research Project of Baishanzu National Park (Grant No. 2021KFLY06).
Appendix I
Data type: COL.
Explanation note: Taxa and Genbank accessions involved in the present study. Missing sequences are indicated by a double slash (//). Accession numbers in bold are newly generated sequences.