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Research Article
 Aster xuelinii (Astereae, Asteraceae), a new species growing on moist rocks from Gansu Province, China
expand article infoZengfu Bai‡, Zhihua Zhang‡, Guojin Zhang§, Ji Zhang‡
‡ Northwest Normal University, Lanzhou, China
§ Hunan Normal University, Changsha, China

Corresponding author: Guojin Zhang ( guojin_zhang@163.com )

Corresponding author: Ji Zhang ( zhangj@nwnu.edu.cn )

Academic editor: Peter de Lange
© 2025 Zengfu Bai, Zhihua Zhang, Guojin Zhang, Ji Zhang.
This is an open access article distributed under the terms of the CC0 Public Domain Dedication.
Citation: Bai Z, Zhang Z, Zhang G, Zhang J (2025) Aster xuelinii (Astereae, Asteraceae), a new species growing on moist rocks from Gansu Province, China. PhytoKeys 263: 17-23. https://doi.org/10.3897/phytokeys.263.166400
Open Access

Abstract

Aster xuelinii, a new species from Gansu Province, China, is described and illustrated based on morphological and phylogenetic evidence. The new species is superficially similar to A. dolichopodus Y. Ling in that both have nearly entire leaves, synflorescence solitary at branch tips or arranged in corymbiform clusters, and ray floret color. However, it differs from A. dolichopodus in having peduncles 6–9 cm in length and 12–14 ray florets, versus 2.5–15 cm in length and 19–26 ray florets. Phylogenetic analyses of nuclear ribosomal ITS and ETS sequences, as well as the chloroplast trnL-F region, place this new species within the genus Aster, where it forms a well-supported clade with A. taliangshanensis Y. Ling. A. xuelinii differs from A. taliangshanensis in that the latter has stems often purplish-red in the upper part, capitula typically arranged 1–3 at branch tips forming a loosely corymbiform synflorescence, and a higher number of ray florets (50–60), which are bluish-purple. Furthermore, detailed morphological descriptions, diagnostic illustrations, and ecological habitat characteristics are provided, supporting the classification of this new species.

Key words:

Aster, Gansu, molecular phylogeny, morphological characters, new taxon

Introduction

Aster Linnaeus (1753: 872), the type genus of Asteraceae, comprises approximately 187 species (POWO 2025) and is widely distributed across Asia, Europe, and North America (Chen et al. 2011). Plants of this genus occupy diverse habitats, from low-altitude ravines and river valleys to mid-elevation forest edges and meadows, extending up to high-altitude alpine meadows, scree slopes, and glacial zones. This broad distribution demonstrates their remarkable ecological adaptability.

China harbors over 170 Aster species, including taxa formerly classified in segregate genera such as Heteropappus Less. and Doellingeria Nees (Li and Liu 2002; Li and Zhang 2004; Li et al. 2017, 2020, 2021; Xiao et al. 2019a, b; Xiong et al. 2019; Zhang et al. 2015, 2019). Modern studies identify the Qinghai–Tibet Plateau and Yunnan–Guizhou Plateau as the primary centers of diversity for the genus (Xiao et al. 2019a).

During 2024 fieldwork in Gansu Province, an undescribed Aster species was collected at a damp wall close to a river. Following morphological examination and phylogenetic analyses, we confirm its status as a novel taxon, naming it Aster xuelinii, and provide a detailed description with comprehensive diagnostic characters herein. As demonstrated by Zhang et al. (2019), Mitsui et al. (2011), and Mitsui and Setoguchi (2012), streamside-adapted species frequently exhibit narrow leaves – a morphological adaptation that minimizes mechanical stress from flowing water.

Materials and methods

Morphological observations

Morphological data were collected during field observations conducted in Xiaolongshan National Nature Reserve, Hui County, Gansu Province. Voucher specimens were photographed with a Nikon D750 digital camera and deposited in the Herbarium of the College of Life Sciences, Northwest Normal University (NWTC) (https://laifu.nwnu.edu.cn/3873/list.htm). The description of the new species Aster xuelinii was conducted using stereomicroscopy on both fresh and dried specimens, with all measurements based exclusively on living material. A comparative analysis was conducted between the target species and its morphologically similar congenerics, particularly A. dolichopodus, to delineate diagnostic characteristics.

Molecular systematics

Taxon sampling

Molecular phylogenetic analyses were conducted using sequences from three regions: ITS, ETS (White et al. 1990; Baldwin and Markos 1998; Linder et al. 2000; Stanford et al. 2000; Markos and Baldwin 2001), and trnL-F (Taberlet et al. 1991). The study included 16 taxa, with Chrysanthemum indicum L. and Callistephus chinensis (L.) Nees designated as outgroups following previous studies (Li et al. 2012; Zhang et al. 2015). Sequences for 14 species were retrieved from GenBank. Voucher specimens for newly sequenced samples are deposited in the NWTC Herbarium. Voucher information and GenBank accession numbers are provided in Suppl. material 1.

DNA extraction, amplification, and sequencing

Leaf tissues were collected in the field and dried in silica gel. DNA extraction, purification, and sequencing followed the protocol described by Zhang et al. (2015). For PCR amplification, ITS and ETS regions were amplified using the methods of Linder et al. (2000), while the trnL-F region followed Zhang et al. (2015). Specific primers employed were ITS primers from Linder et al. (2000); ETS primers “Ast-8” (Markos and Baldwin 2001) and “18S-IGS” (Baldwin and Markos 1998); and trnL-F primers “c” and “f” (Taberlet et al. 1991).

Phylogenetic analysis

Sequence alignments were performed using the MAFFT online version (Katoh et al. 2017), followed by manual adjustment in BioEdit v7.2 (Hall 1999). The optimal DNA substitution models were selected under the Akaike Information Criterion (AIC) using jModelTest v2.1.7 (Darriba et al. 2012). The GTR+G model was applied to ETS and ITS datasets (White et al. 1990; Baldwin and Markos 1998; Linder et al. 2000; Stanford et al. 2000; Markos and Baldwin 2001), while the TVM+G model was used for trnL-F data (Taberlet et al. 1991). The three sequence regions were subsequently concatenated for phylogenetic analysis. Maximum likelihood (ML) analyses were carried out in IQ-TREE v2 (Minh et al. 2020) with 1,000 bootstrap replicates. The optimal models for gene partitions were determined by ModelFinder (Kalyaanamoorthy et al. 2017).

Taxonomic treatment

Aster xuelinii Z.F.Bai, sp. nov.

urn:lsid:ipni.org:names:77369253-1
Fig. 1

Type.

China • Gansu: Hui County, damp stone wall, elev. 800–1100 m, 9 August 2024, Zengfu Bai & Xuelin Chen 20240043 (holotype NWTC!; isotypes GAUF!).

Figure 1. 

Habitat and morphology of Aster xuelinii. A. habitat; B. Habit; C. Basal leaves; D. Cauline leaves; E. Synflorescence; F. Capitulum in frontal view; G. Capitulum in lateral view; H. Disk florets; I. Ray florets.

Diagnosis.

This new species resembles A. dolichopodus superficially. Both have linear – lanceolate cauline leaves and long pedicels. However, the new species differs by having fewer than 15 ray florets (vs. 19–26), stems that are caespitose, pendent, or rarely ascending, and slender (vs. simple, sometimes caespitose, erect, stout stems). It grows in moist habitats (vs. dry habitats).

Description.

Perennial herbs, 30–70 cm tall. Rhizomes short, slightly thick, woody. Stems caespitose, pendent, or rarely ascending, slender, unbranched except for inflorescence, shortly pubescent, with many basal rosette leaves and cauline leaves. Rosette leaves lanceolate, 4–10 × 0.8–1.2 cm, apex acute, base gradually narrowing, strigose, margin serrately one- to two-toothed, petiole 3–5 cm long; lower cauline leaves similar to rosette leaves, sessile, narrowly lanceolate, 4–8 × 0.6–1.4 cm, margin entire or 1-toothed, base gradually narrowing, apex acute, both surfaces of the leaf sparsely scabrous; middle to upper leaves sessile, lanceolate to linear-lanceolate, 3–7 × 0.4–0.7 cm, entire or rarely with a single tooth. Synflorescence leaves lanceolate to linear-lanceolate, 0.5–3 × 0.1–0.4 cm. Capitula 1-6 in terminal corymbiform synflorescences, sometimes solitary; peduncles 6–9 cm long, with linear ca. 2–3.5 mm in diam. bracts. Involucres hemispherical, ca. 5 mm long, 7–15 mm in diameter; phyllaries 5–7-seriate, imbricate, coriaceous, with broadly scarious and shortly ciliate. Outer bracts shorter than inner ones: outer ones lanceolate, only the outermost basally covered with short scabrous hairs; inner ones oblanceolate. True ray 12–14, pale purple, glabrous, 5–9 × 1.2–2 mm; corolla tube 4–6 mm long, apex slightly 2–3-lobed. Disk florets numerous, perfect; tubular yellowish-green, tube 3–4 mm long, glabrous, shallowly 5-lobed; lobes narrowly triangular. Pappus 1-seriate, erect and persistent, off-white in color with minute pubescence adaxially, reaching the base of the corolla lobes or equaling the tube in length. Achenes of both florets similar, narrowly oblong, ca. 2 mm long and 1 mm wide, strigose.

Phenology.

Flowering and fruiting from late June to September.

Etymology.

This distinctive designation honors the substantial contributions made by Chinese botanist Xuelin Chen to botanical diversity surveys in Gansu Province over many years. Hence, the Chinese name “学林紫菀 (xué lín zĬ wăn)” is suggested.

Distribution and habitat.

Aster xuelinii is only known from its type locality, Hui County, Gansu Province, China. This new species grows on moist rock slopes at elevations of 800–1000 meters (Fig. 2).

Figure 2. 

Distribution of Aster xuelinii.

Systematic position.

Based on molecular phylogenetic analyses, the new species is closely related to A. taliangshanensis, and both species are recognized as members of Aster sect. Aster. in Flora of China (Chen et al. 2011) (Fig. 3).

Figure 3. 

Cladogram of the maximum likelihood (ML) phylogenetic tree of representative Aster species. Phylogenetic tree based on combined data (ITS, ETS, and trnL-F), showing the position of Aster xuelinii. Numbers at nodes represent maximum likelihood bootstrap percentages. The two specimens of the new species Aster xuelinii are marked as red.

Key to distinguish Aster xuelinii from the updated key to the species of Aster section Aster.

1 Woody herbs or subshrubs, open corymbiform synflorescences A. smithianus
– Perennial herbs, corymbiform synflorescences 2
2 Ray florets more than 50 A. taliangshanensis
– Ray florets fewer than 50 3
3 Phyllaries 5–7-seriate. Ray florets 12–14, pale purple A. xuelinii
– Phyllaries 3 or 4-seriate. Ray florets 19-26, light purple to purple A. dolichopodus

Acknowledgements

We thank Dr. Alexander Schmidt-Lebuhn and Dr. Mailhos for conducting a thorough review of the manuscript. We also thank NWTC for specimen preservation.

Additional information

Conflict of interest

The authors have declared that no competing interests exist.

Ethical statement

No ethical statement was reported.

Use of AI

No use of AI was reported.

Funding

Common key technologies for the enhancement of the Lanzhou lily industry: research, development, and integrated application (GXH20220617-5); Core generic technologies for upgrading the Lanzhou lily industry: R&D and systemic implementation (Lankezi 2023.69); Germplasm innovation and industrial upgrading of Lanzhou lily: R&D and application of core generic technologies (2023CYZC-13).

Author contributions

BZF: performed data analysis and drafted the manuscript; ZZH: conceived the study and designed the experiments; ZGJ: conceived the study, collected and identified the sample species, and curated the data; ZJ: conceived the study, acquired funding, and critically reviewed the manuscript. All authors have read and agreed to the contents of the manuscript.

Data availability

All of the data that support the findings of this study are available in the main text or Supplementary Information.

References

  • Baldwin BG, Markos S (1998) Phylogenetic utility of the external transcribed spacer (ETS) of 18S-26S rDNA: Congruence of ETS and ITS trees of Calycadenia (Compositae). Molecular Phylogenetics and Evolution 10: 449–463. https://doi.org/10.1006/mpev.1998.0545
  • Chen YL, Brouillet L, Semple JC (2011) Aster. In: Wu ZY, Raven PH, Hong DY (Eds) Flora of China 20-21. St. Science Press, Beijing, Missouri Botanical Garden Press, Louis, 574–632.
  • Darriba D, Taboada GL, Doallo R, Posada D (2012) jModelTest 2: More models, new heuristics and parallel computing. Nature Methods 9(8): 772. https://doi.org/10.1038/nmeth.2109
  • Hall TA (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series 41: 95–98
  • Kalyaanamoorthy S, Minh BQ, Wong TKF, von Haeseler A, Jermiin LS (2017) ModelFinder: Fast model selection for accurate phylogenetic estimates. Nature Methods 14(6): 587–589. https://doi.org/10.1038/nmeth.4285
  • Katoh K, Rozewicki J, Yamada KD (2017) MAFFT online service: Multiple sequence alignment, interactive sequence choice and visualization. Briefings in Bioinformatics: bbx108. https://doi.org/10.1093/bib/bbx108
  • Li WP, Yang FS, Jivkova T, Yin GS (2012) Phylogenetic relationships and generic delimitation of Eurasian Aster (Asteraceae: Astereae) inferred from ITS, ETS and trnL-F sequence data. Annals of Botany 109(7): 1341–1357.
  • Li WP, Liu SX (2002) Aster jishouensis (Asteraceae), a new species from Hunan, China. Acta Phytotaxonomica Sinica 40(5): 455–457.
  • Li WP, Zhang ZG (2004) Aster shennongjiaensis (Asteraceae), a new species from central China. Botanical Bulletin of Academia Sinica 45: 95–99.
  • Li Z, Yin GS, Tang M, Li WP (2017) Aster oliganthus (Asteraceae, Astereae), a new species from western Sichuan, China, based on morphological and molecular data. Phytotaxa 326(1): 54–62. https://doi.org/10.11646/phytotaxa.326.1.4
  • Linder CR, Goertzen LR, Heuvel BV, Francisco-Ortega J, Jansen RK (2000) The complete external transcribed spacer of 18S-26S rDNA: Amplification and phylogenetic utility at low taxonomic levels in Asteraceae and closely allied families. Molecular Phylogenetics and Evolution 14: 285–303. https://doi.org/10.1006/mpev.1999.0706
  • Markos S, Baldwin BG (2001) Higher-level relationships and major lineages of Lessingia (Compositae, Astereae) based on nuclear rDNA internal and external transcribed spacer (ITS and ETS) sequences. Systematic Botany 26: 168–183.
  • Minh BQ, Hahn MW, Lanfear R (2020) New methods to calculate concordance factors for phylogenomic datasets. Molecular Biology and Evolution 37: 2727–2733. https://doi.org/10.1093/molbev/msaa106
  • Mitsui Y, Setoguchi H (2012) Demographic histories of adaptively diverged riparian and non-riparian species of Ainsliaea (Asteraceae) inferred from coalescent analyses using multiple nuclear loci. BMC Evolutionary Biology 12(1): 254. https://doi.org/10.1186/1471-2148-12-254
  • Stanford AM, Harden R, Parks CR (2000) Phylogeny and biogeography of Juglans (Juglandaceae) based on matK and ITS sequence data. American Journal of Botany 87: 872–882. https://doi.org/10.2307/2656895
  • Taberlet PT, Gielly L, Patou G, Bouvet J (1991) Universal primers for amplication of three non-coding regions of chloroplast DNA. Plant Molecular Biology 17: 1105–1109. https://doi.org/10.1007/BF00037152
  • White TJ, Bruns T, Lee S, Taylor J (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (Eds) PCR Protocols: A Guide to Methods and Application. San Diego, Academic Press, 315–322. https://doi.org/10.1016/B978-0-12-372180-8.50042-1
  • Xiong YC, Li Z, Xiao JW, Li WP (2019) Aster saxicola sp. nov. (Asteraceae, Astereae), a new species from Guizhou, China: Evidence from morphological, molecular and cytological studies. Nordic Journal of Botany 37: e02364. https://doi.org/10.1111/njb.02364
  • Zhang GJ, Hu HH, Zhang CF, Tian XJ, Peng H, Gao TG (2015) Inaccessible biodiversity on limestone cliffs: Aster tianmenshanensis (Asteraceae), a new critically endangered species from China. PLoS ONE 10(8): e0134895. https://doi.org/10.1371/journal.pone.0134895
  • Zhang GJ, Hu HH, Gao TG, Gilbert MG, Jin XF (2019) Convergent origin of the narrowly lanceolate leaf in the genus Aster, with special reference to an unexpected discovery of a new Aster species from East China. PeerJ 7: e6288. https://doi.org/10.7717/peerj.6288

Supplementary material

Supplementary material 1 

Voucher information and GenBank accession numbers

Zengfu Bai, Zhihua Zhang, Guojin Zhang, Ji Zhang

Data type: docx

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.
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