Strobilanthes danxiaensis, a new species of Acanthaceae endemic to Danxia Mountain in Guangdong Province, China

69 Strobilanthes danxiaensis, a new species of Acanthaceae endemic to Danxia Mountain in Guangdong Province, China Bao-Huan Wu1,2 , Ji-Fang Zhang1,2, Jian-Qiang Guo3, Wei Wang4, Se-Ping Dai1,2, Guo-Feng Liu1,2, Qiang Fan5 1 Guangzhou Institute of Forestry and Landscape Architecture, Guangzhou 510405, China 2 Guangzhou Collaborative Innovation Center on Science-Tech of Ecology and Landscape, Guangzhou 510405, China 3 Administrative Commission of Danxiashan National Park, Shaoguan 512300, China 4 Yunluo Botanical Garden, Guangzhou 510304, China 5 Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China Corresponding author: Ji-Fang Zhang ([email protected]) Copyright: © Bao-Huan Wu 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). Research Article Abstract Strobilanthes danxiaensis, a new species endemic to the Danxia Mountain region of Guangdong, China, is described herein. Phylogenetic analysis based on nuclear ITS sequences indicates that S. danxiaensis, S. japonica, S. tetrasperma and S. austrosinensis form a well-supported clade. Morphologically, S. danxiaensis is most similar to S. tetrasperma and S. austrosinensis; however, it is readily distinguished from S. tetrasperma by its longer corolla, much broader oblong–obovate and emarginate corolla lobes, and a longer style. It further differs from S. austrosinensis in having larger oblong–obovate, emarginate corolla lobes, shorter filaments, and a longer style. The integration of morphological and molecular evidence supports the recognition of S. danxiaensis as a distinct species. Key words: Biodiversity, Shaoguan, taxonomy Introduction Acanthaceae is a large family with approximately 220 genera and over 4,000 species, widely distributed in tropical and subtropical regions (Hu and Tsui 2002, Hu et al. 2011, Deng 2019). Strobilanthes Blume, as the second most species-rich genus within Acanthaceae, comprises more than 400 species (Hu and Tsui 2002; Hu et al. 2011; Deng 2019; Chen et al. 2020). The taxonomic history of Strobilanthes is complex, challenged by the high diversity in its vegetative and reproductive traits. Historically, some taxonomists segregated it into numerous smaller genera based on morphological characters (Bremekamp 1944, Carine and Scotland 2002), but molecular phylogenetic studies have suggested that these segregate genera should be placed together under a broader concept of Strobilanthes (Moylan et al. 2004). This broader concept has been increasingly accepted by the scientific community (Deng et al. 2006; Wood and Scotland 2009, 2021; Hu et al. 2011; Wood 2014). Strobilanthes species are primarily distributed in tropical and subtropical regions of Asia, with China being one of the centers of diversity for the genus, having more than 120 species recorded, many of which are endemic (Hu et al. 2011). Academic editor: Alan Paton Received: 19 September 2025 Accepted: 30 November 2025 Published: 16 December 2025 Citation: Wu B-H, Zhang J-F, Guo J-Q, Wang W, Dai S-P, Liu G-F, Fan Q (2025) Strobilanthes danxiaensis, a new species of Acanthaceae endemic to Danxia Mountain in Guangdong Province, China. PhytoKeys 268: 69–79. https://doi.org/10.3897/ phytokeys.268.172546 PhytoKeys 268: 69–79 (2025) DOI: 10.3897/phytokeys.268.172546 70 PhytoKeys 268: 69–79 (2025), DOI: 10.3897/phytokeys.268.172546 Bao-Huan Wu et al.: Strobilanthes danxiaensis, a new species from Guangdong Province, China Danxia Mountain in Guangdong represents a typical Danxia landform, characterized by steep cliffs, isolated peaks, deep ravines, and a striking mosaic of microhabitats ranging from exposed rocky slopes to humid valley bottoms. These geomorphological and microclimatic conditions have supported high levels of plant diversity and local endemism. In recent years, several new species have been continuously discovered and described from this region (Zhao et al. 2021; Fu et al. 2022; Xu et al. 2022; Huang et al. 2023; Wang et al. 2023). In the past two years, we discovered an additional species of Strobilanthes in Danxia Mountain, and subsequent study confirmed that it represents a new species, which is formally described in this paper. Materials and methods Field survey and specimen collection Multiple field surveys were conducted in the Danxia Mountain region of Guangdong Province from 2024 to 2025. During these surveys, we recorded detailed ecological information about the new species, including its habitat and co-occurring plants. We also made on-site observations, measuring and taking photographs of the plant’s morphological features, such as leaves, inflorescence, corolla, stamens, and fruits. Type specimens were collected and deposited in the herbarium of Sun Yatsen University (SYS) and the herbarium of South China Botanical Garden (IBSC). Morphological comparison and literature review To confirm the taxonomic status of the new species, we conducted a detailed morphological comparison of the collected specimens with other Strobilanthes species from China and neighboring regions. Morphological data of the new species were measured by rulers and recorded based on nine individuals, and the comparison was conducted primarily using descriptions in relevant literature (Bremekamp 1944; Carine and Scotland 2002; Hu and Tsui 2002; Deng et al. 2006; Deng et al. 2009; Wood and Scotland 2009, 2021; Hu et al. 2011; Chen et al. 2019; Thomas et al. 2019; Nilanthi et al. 2023; Hu et al. 2024; Kladwong and Chantaranothai 2024) as well as online herbarium resources (e.g. the Chinese Virtual Herbarium, CVH). Molecular phylogenetic analysis A total of 40 samples representing 37 species of Strobilanthes and one species of Ruellia L. were sampled for phylogenetic analysis, including the newly described species. Among these, the new species, S. austrosinensis Y.F.Deng & J.R.I.Wood and S. tetrasperma (Champ. ex Benth.) Druce were newly collected and sequenced for this study. The remaining 36 samples were represented by ITS sequences downloaded from GenBank. GenBank accession numbers for all sequences, including newly generated data, are listed in Table 1. Ruellia brittoniana Leonard was selected as the outgroup based on previous phylogenetic studies (Fernandes et al. 2025). For the newly sequenced samples, fresh leaf material was silica-gel-dried in the field, and total genomic DNA was extracted using the CTAB protocol (Doyle and Doyle 1987). The extracted DNA was sent to Jierui Biotech (Guangzhou, China) for 71 PhytoKeys 268: 69–79 (2025), DOI: 10.3897/phytokeys.268.172546 Bao-Huan Wu et al.: Strobilanthes danxiaensis, a new species from Guangdong Province, China sequencing on the Illumina NovaSeq X Plus platform in PE150 mode. Raw reads were assembled into complete ribosomal DNA (rDNA) contigs using GetOrganelle v1.7.5 (Jin et al. 2020). The nuclear ribosomal internal transcribed spacer (ITS) region was extracted from the assembled rDNA contigs using BLAST+ (Camacho et al. 2009). A dataset was then compiled by combining the newly generated ITS sequences with all 36 publicly available ITS accessions in GenBank. Sequences were aligned using MAFFT v7.453 (Nakamura et al. 2018) with the L-INS-i algorithm, and ambiguously aligned regions were excluded using Gblocks 0.91b (Talavera and Castresana 2007) with the strict-plus option. Maximum-likelihood (ML) phylogenetic inference was conducted using IQ-TREE v1.6.12 (Nguyen et al. 2015) under the best-fitting substitution model (TNe+R3), selected by ModelFinder (Kalyaanamoorthy et al. 2017) based on the Bayesian information criterion. Branch support was assessed with 10,000 ultrafast bootstrap replicates. The phylogenetic tree was visualized and annotated using the Interactive Tree of Life (iTOL) v6 (Letunic and Bork 2024). Results Morphological characteristics of the new species Strobilanthes danxiaensis is a perennial herb up to 80 cm tall. It is morphologically similar to Strobilanthes tetrasperma and S. austrosinensis by having isophyllous leaves that are ovate to elliptic with an attenuate base and acute apex, pubescent corolla, calyx subequally 5-lobed to the base, 4-seeded capsule, and erect anthers. However, it differs from S. tetrasperma in having a longer corolla (2.8–4 cm vs. 1.5–2 cm), larger corolla lobes that are oblong–obovate, ca. 1 × 1 cm and emarTable 1. GenBank accession numbers of the sequences used in this study. Species Accession No. Species Accession No. Strobilanthes danxiaensis PX368963 S. isophylla AY489352 S. austrosinensis PX368964 S. japonica AY489356 S. tetrasperma 1 PX532389 S. kunthiana AY489377 S. tetrasperma 2 PX532390 S. lamiifolia AY489347 S. alata AY489360 S. lawsonii MT896161 S. anamallaica MT876221 S. lawsonii AY489375 S. anceps AY489395 S. lupulina AY489397 S. andamanensis AY489386 S. micrantha AY489388 S. asper AY489399 S. neilgherrensis AY489373 S. attenuata AY489344 S. pulcherrima AY489368 S. barbata AY489382 S. punctata AY489396 S. bibracteata AY489359 S. repanda AY489366 S. cernua AY489361 S. rubicunda AY489370 S. ciliata AY489381 S. steenisiana AY489357 S. decurrens AY489390 S. stenodon AY489372 S. filiformis AY489353 S. versicolor MT914278 S. foliosa OM436003 S. virendrakumarana MT896160 S. habracanthoides AY489369 S. walkeri AY489391 S. imbricata AY489362 S. walkeri MT889663 S. involucrata AY489358 Ruellia brittoniana EF214458 72 PhytoKeys 268: 69–79 (2025), DOI: 10.3897/phytokeys.268.172546 Bao-Huan Wu et al.: Strobilanthes danxiaensis, a new species from Guangdong Province, China ginate (vs. oblong, ca. 4 × 5 mm and apex obtuse), and a longer style (3 cm vs. 1.5 cm). Compared to S. austrosinensis, S. danxiaensis has larger oblong–obovate, emarginate corolla lobes (ca. 1 × 1 cm vs. ovate-elliptic, ca. 5 mm in length), shorter filaments (shorter pair ca. 2 mm, longer pair ca. 6 mm vs. shorter pair 6 mm, longer pair 8 mm), and a longer style (3 cm vs. 1.5 cm). These combined characters clearly separate S. danxiaensis from both of its closest relatives. A more detailed morphological comparison of these species was summarized in Table 2. Phylogenetic analysis After aligning the ITS sequences of 40 samples using MAFFT and extracting conserved regions with Gblocks, the final matrix contained 345 characters, of which 105 were variable and 45 were parsimony-informative. The phylogenetic analysis (Fig. 1) shows that S. danxiaensis forms a strongly supported clade with S. japonica (BS = 96%). This clade is further grouped with two samples of S. tetrasperma to form another well-supported clade (BS = 93%). S. austrosinensis forms the sister group to the clade comprising S. danxiaensis, S. japonica, and S. tetrasperma, with strong support (BS = 90%). Table 2. Morphological comparison of Strobilanthes danxiaensis, S. austrosinensis and S. japonica. Character Strobilanthes danxiaensis S. tetrasperma S. austrosinensis S. japonica Height up to 80 cm 30–50 cm to 50 cm 20–50 cm Stem white tomentose retrorsely pubescent along sulci, glabrescent bifariously pubescent with reflexed large-celled trichomes glabrous Leaf blade ovate to elliptic, 6.5–10 × 3.8–5.5 cm ovate, elliptic, or oblong, 1.5–11 × 1–4.5 cm elliptic to suborbicular, 2–8 × 1–4.5 cm narrowly elliptic to lanceolate, 2–5 × 0.5–1.8 cm Leaf adaxial surface sparsely puberulous glabrous pilose and hirsute glabrous Leaf abaxial surface tomentose along veins glabrous pilose along veins glabrous Petiole 0.3–1.1 cm, tomentose 0.5–2.5 cm, sulcate, glabrous 0–2 cm, bifariously hirsute 2–5 cm, pubescent Bracts leaflike, obovate to obovate-spatulate, 1–2 × 0.5–1 cm leaflike, obovate to spatulate, 1–1.5 × 0.4–0.5 cm leaflike, broadly obovate-spatulate, 1.5–1.8 × 0.5–0.8 cm imbricate, oblanceolate to oblong-lanceolate, 7–10 × 2–3 mm Bracteoles linear to oblanceolate, 0.8–0.9 × 0.1–0.2 cm linear, 5–6 × ca. 1 mm spatulate, 8–11 × 1–2.5 mm linear, ca. 5 mm Calyx 0.8–1.1 cm long, densely pubescent on both surfaces 0.5–0.7 cm long, glabrous except for large-celled trichomes on margin, densely covered with cystoliths 1–1.2 cm long, outside pilose, inside subglabrous, margin ciliate 0.6–0.7 cm long, margin ciliate Corolla pale purple to whitish, 2.8–4 cm purple to purplish blue, 1.5–2 cm bluish purple, 2.2–2.8 cm purplish white or white, ca. 1.5 cm Corolla lobes oblong to obovate, ca. 10 × 10 mm, emarginate at apex oblong, ca. 4 × 5 mm, apex obtuse ovate-elliptic, ca. 5 mm long oblong-elliptic, 5–6 mm long Filaments shorter pair ca. 2 mm, longer pair ca. 6 mm shorter pair ca. 2 mm, longer pair ca. 5 mm shorter pair ca. 6 mm, longer pair ca. 8 mm shorter pair ca. 8 mm, longer pair ca. 12 mm Ovary cylindrical, upper 2/3 pubescent ovoid, ca. 3 mm, hispid at tip ovoid, glabrous except comose tip glabrous Style ca. 3 cm ca. 1.5 cm ca. 1.5 cm ca. 1.2 cm Phenology flowering November–January, fruiting march flowering July–December flowering July–September, fruiting October–November flowering August– September, fruiting October–November 73 PhytoKeys 268: 69–79 (2025), DOI: 10.3897/phytokeys.268.172546 Bao-Huan Wu et al.: Strobilanthes danxiaensis, a new species from Guangdong Province, China Taxonomic treatment Strobilanthes danxiaensis B.H.Wu, J.F.Zhang & J.Q.Guo, sp. nov. urn:lsid:ipni.org:names:77373766-1 Fig. 2 Chinese name: “dān xiá mă lán” (丹霞马蓝) Type. China • Guangdong Province: Shaoguan City, Renhua County, Danxia Mountain area, 250 m a.s.l., in moist valleys, 4 December 2024, Jian-Qiang Guo and Bao-Huan Wu Lg2024179 (holotype: SYS!; isotype: SYS!; IBSC!). Diagnosis. Morphologically, Strobilanthes danxiaensis is most similar to S. tetrasperma, but differs in its longer corolla (2.8–4 cm vs. 1.5–2 cm), with larger, emarginate oblong–obovate corolla lobes (ca. 1 × 1 cm vs. oblong lobes ca. 4 × 5 mm with obtuse apices), and a much longer style (3 cm vs. 1.5 cm). Description. Perennial herb, up to 80 cm tall. Stems slightly prostrate at base, becoming erect or ascending upwards, quadrangular, white tomentose, gradually Figure 1. Maximum likelihood tree for the Strobilanthes based on the ITS dataset. Bootstrap values are labeled under the branches. Strobilanthes ciliata AY489381 Strobilanthes barbata AY489382 Strobilanthes foliosa OM43600 3 Strobilanthes anamallaica MT876221 Strobilanthes neilgherrensis AY489373 Strobilanthes stenodon AY489372 Strobilanthes lawsonii MT896161 Strobilanthes lawsonii AY489375 Strobilanthes kunthiana AY489377 Strobilanthes filiformis AY489353 Strobilanthes attenuata AY489344 Strobilanthes isophylla AY489352 Strobilanthes lamiifolia AY489347 Strobilanthes cernua AY489361 Strobilanthes alata AY489360 Strobilanthes imbricata AY489362 Strobilanthes repanda AY489366 Strobilanthes anceps AY489395 Strobilanthes virendrakumarana MT896160 Strobilanthes asper AY489399 Strobilanthes walkeri MT889663 Strobilanthes lupulina AY489397 Strobilanthes walkeri AY489391 Strobilanthes micrantha AY489388 Strobilanthes decurrens AY489390 Strobilanthes andamanensis AY489386 Strobilanthes versicolor MT914278 Strobilanthes rubicunda AY489370 Strobilanthes pulcherrima AY489368 Strobilanthes habracanthoides AY489369 Strobilanthes tetrasperma PX532389 SStrobilanthes danxiaensis PX368963 Strobilanthes japonica AY489356 Strobilanthes austrosinensis PX368964 Strobilanthes bibracteata AY489359 Strobilanthes involucrata AY489358 Ruellia brittoniana EF214458 84 Strobilanthes punctata AY489396 79 94 74 68 56 39 93 93 81 59 76 90 97 92 90 93 53 73 94 96 77 54 99 55 97 58 89 96 79 96 93 58 92 98 Strobilanthes tetrasperma PX532390 83 66 Tree scale: 0.1 Strobilanthes steenisiana AY489357 74 PhytoKeys 268: 69–79 (2025), DOI: 10.3897/phytokeys.268.172546 Bao-Huan Wu et al.: Strobilanthes danxiaensis, a new species from Guangdong Province, China Figure 2. Strobilanthes danxiaensis. A. Wild individuals; B. Habitat; C. Flowering branch; D. Leaves; E. Inflorescence; F. Bud; G. Side view of flower; H. Front view of flower; I. Bracts; J. Bracteoles; K. Calyxs; L. Gynoecium; M. Dissected corolla showing stamens; N. Infructescence; O. Dissected capsule. Photographed by Jian-Qiang Guo and Bao-Huan Wu. 75 PhytoKeys 268: 69–79 (2025), DOI: 10.3897/phytokeys.268.172546 Bao-Huan Wu et al.: Strobilanthes danxiaensis, a new species from Guangdong Province, China glabrescent below. Leaves opposite; petiole 0.3–1.1 cm long, white tomentose; blade ovate to elliptic, 6.5–10 × 3.8–5.5 cm, adaxially green and sparsely puberulous with short white hairs, cystoliths absent or sometimes sparsely present, abaxially pale green, tomentose along veins and conspicuously glandular-cystic; lateral veins 4–5(–6) pairs, prominently raised on both surfaces; base attenuate, apex acute; margin crenate-dentate with obtuse teeth. Inflorescences short terminal spikes, 1–4 cm long, often elongating at maturity, bearing 2–4 flowers; rachis tomentose. Bracts leaf-like, obovate to obovate-spatulate, 1–2 × 0.5–1 cm, puberulous on both surfaces, margin shallowly serrate, apex obtuse, base attenuate. Bracteoles linear to oblanceolate, 0.8–0.9 × 0.1–0.2 cm, midrib conspicuous, entire, densely white-hirsute on both surfaces. Calyx 5-lobed almost to base; lobes linear, 0.8–1.1 cm long, midrib prominent, densely pubescent on both surfaces, apex obtuse. Corolla pale purple to whitish, funnel-shaped, 2.8–4 cm long, slightly inflated and curved, externally puberulous, internally pubescent in throat and downward; tube basally cylindrical, ca. 2 mm wide, 1.1–1.3 cm long, gradually widened towards mouth; orifice 1.6–3 cm wide, 2–2.8 cm high; lobes oblong to obovate, subequal, ca. 1 × 1 cm, emarginate at apex. Stamens 4, included; filaments sparsely pubescent; shorter pair ca. 2 mm long, longer pair ca. 6 mm long. Anthers narrowly ellipsoid, ca. 3 mm long. Ovary cylindrical, ca. 3 mm long, upper 2/3 densely pubescent; style ca. 3 cm long, sparsely pubescent. Capsule narrowly ellipsoidal, ca. 1 cm long, ca. 2.5 mm in diam., upper 2/3 pubescent, 4-seeded. Phenology. Flowering from November to January; fruiting in March. Etymology. The specific epithet “danxiaensis” refers to the type locality, Danxia Mountain in Guangdong Province, China, to commemorate this unique landform and the rich plant diversity it harbors. Distribution and habitat. Strobilanthes danxiaensis is known only from Danxia Mountain, Guangdong Province, China. Only three populations have been discovered, with a total of fewer than 100 individuals. They grow in moist valleys at elevations of 350–400 m. Associated species include Maesa perlarius (Lour.) Merr., Alocasia odora (Roxb.) K. Koch, S. dimorphotricha Hance, Oplismenus compositus (L.) P. Beauv., Tectaria devexa Copel., and Lobelia nummularia Lam. Conservation status. Strobilanthes danxiaensis is currently known from only three small populations in moist valleys on Danxia Mountain. However, the species occurs in a rugged and heterogeneous landscape where botanical surveys remain incomplete, and additional suitable habitats in the region have not yet been systematically explored. There is insufficient evidence to formerly assess the species using IUCN guidelines and we consider this species to be Data Deficient (DD). Discussion The taxonomic history of Strobilanthes has long been complex. To date, molecular systematics studies of Strobilanthes remain limited in both scope and taxon sampling. In this study, we used 36 ITS sequences from public databases, combined with four newly sequenced samples, to form an alignment matrix comprising 37 species and reconstructed a maximum likelihood tree. Our molecular analysis yielded unresolved relationships within Strobilanthes, with most clades receiving low support and interclade relationships remaining uncertain. Strobilanthes danxiaensis, characterized by ovate to elliptic leaves with an attenuate base and acute apex, pubescent corollas, calyx 5-lobed to the base, 76 PhytoKeys 268: 69–79 (2025), DOI: 10.3897/phytokeys.268.172546 Bao-Huan Wu et al.: Strobilanthes danxiaensis, a new species from Guangdong Province, China 4-seeded capsules, and erect anthers, is morphologically similar to S. tetrasperma and S. austrosinensis. Because of these morphological similarities, both species were included in the phylogenetic analysis, to clarify their relationships. The molecular results support a close relationship among these species, but indicate that S. japonica is actually the closest relative of S. danxiaensis, with the two forming a strongly supported clade. This clade is subsequently united with S. tetrasperma and S. austrosinensis. Although these findings do not yet provide a definitive framework for infrageneric classification within Strobilanthes, they demonstrate a clear phylogenetic affinity among these four species. Compared with its closest relative, S. japonica, S. danxiaensis has markedly larger leaves (6.5–10 × 3.8–5.5 cm vs. 2–5 × 0.5–1.8 cm), shorter petioles (0.3–1.1 cm vs. 2–5 cm), a longer corolla (2.8–4 cm vs. ca. 1.5 cm), much shorter filaments (shorter pair ca. 2 mm and longer pair ca. 6 mm vs. shorter pair ca. 8 mm and longer pair ca. 12 mm), and a longer style (ca. 3 cm vs. ca. 1.2 cm), all of which clearly differentiate the two species. Concurrently, detailed morphological comparisons corroborate that S. danxiaensis is readily distinguishable from S. japonica, S. tetrasperma, and S. austrosinensis, thereby supporting its recognition as a distinct species. Acknowledgements We are grateful to the curators of the herbaria at IBSC, IBK, PE, SZG, HITBC, and UPS for permitting us to examine their collections and utilize their scanned images of specimens. Additionally, we extend our thanks to Dr. Peng-Wei Li from the Guangxi Institute of Botany for his invaluable assistance in collecting samples of S. austrosinensis. 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 This study was supported by Science and Technology Program from Forestry Administration of Guangdong Province (Grant no. 2023KJCX002). Author contributions Bao-Huan Wu and Ji-Fang Zhang are the main authors of the article, and everyone else participated in the writing. Jian-Qiang Guo and Qiang Fan participated in the taxonomic confirmation of the new species and field investigation. Wei Wang participated in data analysis and manuscript revision. Se-Ping Dai and Guo-Feng are the leaders of the research project, responsible for promoting the project. 77 PhytoKeys 268: 69–79 (2025), DOI: 10.3897/phytokeys.268.172546 Bao-Huan Wu et al.: Strobilanthes danxiaensis, a new species from Guangdong Province, China Author ORCIDs Bao-Huan Wu https://orcid.org/0000-0002-0498-0603 Jian-Qiang Guo https://orcid.org/0009-0004-2304-0360 Qiang Fan https://orcid.org/0000-0003-4254-6936 Data availability The original contributions presented in this study are included in the article; further inquiries can be directed to the corresponding authors. References Bremekamp CEB (1944) Materials for a monograph of the Strobilanthinae. Verhandelingen der Koninklijke Nederlandse Akademie van Wetenschappen. Afdeling Natuurkunde 41: 1–306. Camacho C, Coulouris G, Avagyan V, Ma N, Papadopoulos J, Bealer K, Madden TL (2009) BLAST+: Architecture and applications. BMC Bioinformatics 10: 421. https://doi. org/10.1186/1471-2105-10-421 Carine MA, Scotland RW (2002) Classification of Strobilanthinae (Acanthaceae): Trying to classify the unclassifiable? Taxon 51(2): 259–279. https://doi.org/10.2307/1554897 Chen FL, Deng YF, Xiong ZB, Ran JC (2019) Strobilanthes hongii, a new species of Acanthaceae from Guizhou, China. Phytotaxa 388(1): 135–144. https://doi. org/10.11646/phytotaxa.388.1.7 Chen JT, Huang XH, Lv ZY, Kuang TH, Luo J, Deng YF, Deng T (2020) Strobilanthes sunhangii (Acanthaceae), a new species from Tibet, China. PhytoKeys 166: 117–127. https://doi.org/10.3897/phytokeys.166.58831 Deng YF (2019) Transfer of the Philippine species of Hemigraphis Nees to Strobilanthes Blume (Acanthaceae). Phytotaxa 404(5): 1–3. https://doi.org/10.11646/phytotaxa.404.5.3 Deng YF, Wood JRI, Scotland RW (2006) New and reassessed species of Strobilanthes (Acanthaceae) in the flora of China. Botanical Journal of the Linnean Society 150(4): 369–390. https://doi.org/10.1111/j.1095-8339.2006.00473.x Deng YF, Xia NH, Hao ZP, Sun Y (2009) Acanthaceae. In: Wu DL (Ed.) Flora of Guangdong, vol. 9. Guangdong Science & Technology Press, Guangzhou, 95–154. Doyle JJ, Doyle JL (1987) A rapid DNA isolation procedure for small quantities of fresh leaf tissue. Phytochemical Bulletin 19: 11–15. Fernandes MC, Surveswaran S, Sellappan K (2025) Molecular phylogeny of Strobilanthes (Acanthaceae) from the northern Western Ghats of India: Phylogenetic relationships and implications for systematics and biogeography. Nordic Journal of Botany 8: e04678. https://doi.org/10.1002/njb.04678 Fu LF, Xiong C, Monro AK, Fan Q, Chen ZX, Wen F, Xin ZB, Wei YG, Liao WB (2022) Pilea danxiaensis (Urticaceae), a new species in the Danxia landform from Guangdong, China including a description of the entire chloroplast genome. PhytoKeys 204: 109– 119. https://doi.org/10.3897/phytokeys.204.86857 Hu CC, Tsui HP (2002) Acanthaceae. In: Hu CC (Ed.) Flora Reipublicae Popularis Sinicae, vol. 70. Science Press, Beijing, 1–309. [In Chinese] Hu JQ, Deng YF, Wood JRI (2011) Acanthaceae. In: Wu ZY, Raven PH, Hong DY (Eds) Flora of China, vol. 19. Science Press & Missouri Botanical Garden Press, Beijing & St. Louis, 369–477.