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Research Article
Spiradiclis yanii (Rubiaceae), a new species from Guangxi, China
expand article infoYou Nong‡, Li-Qun Lei§, Gui-Yuan Wei‡, Xin-Cheng Qu‡, Zi-Yi Zhao‡, Bin Feng‡, Chuan-Gui Xu‡, Lei Wu|
‡ Guangxi Institute of Chinese Medicine & Pharmaceutical Science, Nanning, China
§ Nanning Botanical Garden, Nanning, China
| Central South University of Forestry and Technology, Changsha, China

Corresponding author: Chuan-Gui Xu ( 313524094@qq.com )

Corresponding author: Lei Wu ( wuleiibk@163.com )

Academic editor: Andre Simões
© 2024 You Nong, Li-Qun Lei, Gui-Yuan Wei, Xin-Cheng Qu, Zi-Yi Zhao, Bin Feng, Chuan-Gui Xu, Lei Wu.
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: Nong Y, Lei L-Q, Wei G-Y, Qu X-C, Zhao Z-Y, Feng B, Xu C-G, Wu L (2024) Spiradiclis yanii (Rubiaceae), a new species from Guangxi, China. PhytoKeys 247: 173-181. https://doi.org/10.3897/phytokeys.247.123867
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Abstract

Spiradiclis yanii Y.Nong & L.Wu (Rubiaceae), a new species from Guangxi, China, is described and illustrated. This new species is most similar to S. tomentosa, but it can be easily distinguished by being densely multicellular villous, leaves narrow elliptic or oblanceolate, apex acute or shortly acuminate, stipules 2–4, linear or linear lanceolate, 4–8 mm, densely villous, corolla tube 3 mm, sparsely pubescent inside, flower homomorphism, lobes 3–5, stamens arising at the base of the tube, stigma 2-lobed, lobes ovoid, slightly swollen, 0.2 mm. The habitat of Spiradiclis yanii is extremely fragile. Therefore, this species deserves close attention and protection.

Key words

Longan, limestone, new species, sinkhole, taxonomy

Introduction

Spiradiclis Blume most closely resembles Ophiorrhiza L. and the two genera are in the same tribe Ophiorrhizeae, based on morphological characters (Verdcourt 1958; Darwin 1976; Lo 1999; Chen and Taylor 2011; Wu et al. 2019) and molecular evidence (Bremer 2009; Rydin et al. 2009; Wikström et al. 2013). Robbrecht (1988, 1993) accepted earlier conclusions that Spiradiclis is related to Ophiorrhiza; a more recent study, based on molecular data, suggests that the situation may be more complex and calls into question the separation of these genera (Rydin et al. 2009). Even so, the monophyly of the two genera is questioned (Razafimandimbison and Rydin 2019). However, Spiradiclis is morphologically different from Ophiorrhiza by its linear-oblong or subglobose capsules with four valves (vs. obcordate and compressed capsules with two valves) when mature. Since the delimitation and relationship of the two genera still need further research, we prefer to accept the traditional concept of Spiradiclis here due to its unique capsule form. Subsequently, more than 20 new species of Spiradiclis have been discovered in the last decade (e.g. Wang 2016; Zhang et al. 2018; Pan et al. 2019; Tong et al. 2020; Cai et al. 2022).

During our field surveys in Longan County, Guangxi in March 2024, we found a special Spiradiclis population in flower and fruit that was morphologically similar to the species S. tomentosa D. Fang & D. H. Qin. However, this special population is distinctly different from S. tomentosa, based on being densely multicellular villous, leaves elliptic or oblanceolate, apex acute or shortly acuminate, mid-vein flat adaxially and convex abaxially, stipules 2–4, densely villous. Therefore, we proposed that this special population may represent a new species after we carried out more observations and examining many specimens of Spiradiclis from the Herbaria PE, IBK, GXMI and KUN and consulting relevant literature (Lo et al. 1983; Wang 2002; Wang et al. 2015; Wu et al. 2015, 2016, 2019; Pan et al. 2016; Liu et al. 2017; Zhang et al. 2018; Wen et al. 2019; Li et al. 2021; Song et al. 2022). Finally, we carried out one more field survey to confirm that the unusual plant is a species of Spiradiclis new to science and we describe it below.

Materials and methods

Morphology

The new species was described, based on field observations that were made in March 2024 and examination of herbarium specimens at GXMI. Other related Spiradiclis species were examined, based on online images from the Kew Herbarium Catalogue (http://apps.kew.org/herbcat/gotoHomePage.do) and JSTOR Global Plants (http://plants.jstor.org/) and PE, IBK and KUN. Morphological characters that distinguish it from all other species in the genus of Spiradiclis are used. We also observed living plants of the new species at flowering and fruiting time (March). We observed characters of stems, leaves, pedicels, flowers, receptacles, petals, stamens, gynoecium, carpels, size of flowers, size and shape of petals, number of stamens and the shape of gynoecium and fruit.

Descriptions were written from herbarium specimens. Measurements were made with a tape measure and calipers. The structure of the indumentum and its distribution were observed and described under a dissecting microscope at magnifications of more than 20×. Additional information on locality, habitat, ecology, plant form and fruits were collected in the field and taken from herbarium labels. The conservation threat assessment followed IUCN Categories and Criteria (IUCN 2022).

Results and discussion

Taxonomy

Spiradiclis yanii Y.Nong & L.Wu, sp. nov.

urn:lsid:ipni.org:names:77350291-1
Figs 1, 2, 3, 4 Chinese name: yán shì luó xù cǎo (严氏螺序草)

Diagnosis

Spiradiclis yanii is most similar to S. tomentosa, but is different in being densely villous without knots (vs. densely grey-viscid multicellular tomentose); leaves narrow elliptic or oblanceolate (vs. oblanceolate, obovate or rarely elliptic); apex acute or shortly acuminate (vs. apex cuspidate to rounded); mid-vein flat adaxially and convex abaxially (vs. mid-rib and lateral veins nearly flat on both sides); stipules 2–4, linear or linear lanceolate, 4–8 mm, densely villous (vs. stipules persistent, triangular, 8–22 mm, tomentose); corolla tube 3 mm, sparsely pubescent inside (vs. tube 6–8 mm, glabrous inside); lobes 3–5 (vs. lobes 5); stamens arising at the base of the tube (vs. located at the throat of the corolla); stigma 2-lobed, lobes ovoid, slightly swollen, 0.2 mm (vs. stigma deeply bifid with linear lobes, 1–1.5 mm). At first glance, it also looks similar to S. villosa X. X. Chen & W. L. Sha, but differs by its leaves narrow elliptic or oblanceolate, 5–10 × 2–2.5 cm, densely villous adaxially and abaxially (vs. leaves oblong-elliptic or obovate-elliptic, 10–25 × 3–8 cm, adaxially dark brown pubescent, abaxially densely brown villous), petiole 0.5–1 cm (vs. petiole 3.5–7 cm), stipules 2–4, linear or linear lanceolate, 4–8 mm, densely villous (vs. stipules 2-lobed, densely dark brown villous, lobes laciniate, 15–30 mm). More detailed morphological differences amongst the three species are shown in Table 1.

Figure 1. 

Habitat of Spiradiclis yanii Y.Nong & L.Wu on cliffs at the bottom of the sinkhole. Photographed by YN.

Table 1.
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Main morphological differences amongst Spiradiclis yanii, S. tomentosa and S. villosa.

Morphological traits S. yanii S. tomentosa S. villosa
Plant height 5–25 cm 3–23 cm 30–50 cm
Stems densely multicellular villous densely grey-viscid multicellular tomentose densely dark brown villous
Leaves elliptic or oblanceolate, 5–10 × 2–3 cm oblanceolate, obovate or rarely elliptic, 3.5–14 × 1.5–5 cm oblong-elliptic or obovate-elliptic, 10–25 × 3–8 cm
Pedicel 0.5–1 cm 0.5–4.5 cm 3.5–7 cm
Stipules 2–4, linear or linear lanceolate, 4–8 mm, densely villous persistent, triangular, 8–22 mm, tomentose 2-lobed, lobes laciniate, 15–30 mm. densely dark brown villous
Corolla tube 3 mm, sparsely pubescent inside 6–8 mm, glabrous inside Inflorescences and flowers not seen
Stamens arising at the base of the tube, not protruding arising at the throat of the corolla, slightly protruding –
Style and stigma style 2–3 mm, lobes ovoid, slightly swollen, 0.2 mm style 6–7 mm, stigma is deeply bifurcated, lobes linear, 1–1.5 mm –
Capsule obovate, ca. 1 mm subglobose, ca. 2 mm ovoid, ca. 2 mm

Holotype

China • Guangxi: Longan, 23°03'03"N, 107°22'20"E, alt. 327 m, on the cliff at the bottom of a sinkhole, 7 March 2024, Y Nong NY2024030701 (GXMI) (holotype: GXMI!; isotypes: IBK!).

Description

Perennial herbs, erect, 5–25 cm tall, stems cylindrical, 1–2 branches, densely multicellular villous when young, but grabrous when old;Leaves opposite, leaf blade drying membranous, narrow elliptic or oblanceolate, 5–10 × 2–2.5 cm, densely multicellular villous adaxially and abaxially, base cuneate or acute, apex acuminate or shortly acuminate,petiole 0.5–1 cm, densely villous;Mid-vein flat adaxially and convex abaxially,secondary veins 9–14 pairs; Stipules 2–4, linear or linear lanceolate, 4–8 mm, densely villous. Inflorescence terminal, paniculiform, peduncles 6–15 cm,densely villous,pedicels 3–6 mm,bracts linear, 3–7 mm; Hypanthium portion turbinate, 4 mm, calyx lobes 5, linear or narrow lanceolate, 1.5–2 mm; Flower homomorphism,corolla white, lobes 3–5, ovate, 2–3 mm, outside sparsely pubescent, glabrous inside, tube 3 mm, sparsely pubescent inside; Stamens 5, arising at the base of the tube, not protruding, glabrous, filaments 2 mm, anthers oblong, 0.5 mm; top of the ovary 4-lobed, sparsely pubescent; Ovary 2-loculed, with many ovules, style 2–3 mm, glabrous, stigma 2-lobed, lobes ovoid, slightly swollen, 0.2 mm; Capsule obovate, ca. 1 mm in diam., valves 4, persistent calyx lobes 2–4 mm; Seeds numerous, small and angular.

Figure 2. 

Line drawing of Spiradiclis yanii Y.Nong & L.Wu A flowering branch B flower C ovary and stigma D filaments of stamens and perianth E capsule F seeds G stipules (Drawn by Xin-cheng Qu).

Figure 3. 

Spiradiclis yanii Y.Nong & L.Wu A, B plant (flowering and fruiting) C inflorescence (lateral view) D inflorescence (front view, corolla lobes 3–5) E flower (front view) F stamens, ovary and stigma G infructescence (lateral view) H calyx and bracts I capsule J seeds K leaf (adaxially view) L leaf (abaxially view) M, N stipules (Photographed by Ke-Jian Yan & You Nong, edited by You Nong).

Phenology

Flowering and fruiting in February to March.

Etymology

The new species is named after Mr. Ke-Jian Yan, who worked in Guangxi Institute of Chinese Medicine & Pharmaceutical Science and made many contributions to GXMI, especially in Rubiaceae and Lamiaceae.

Figure 4. 

Digital images of type specimens A Spiradiclis yanii B S. tomentosa C S. villosa.

Distribution and habit

Known only from the southeast of Guangxi, China. It has been mainly found on cliffs at the bottom of a sinkhole at elevations of 320 m.

IUCN red list category

Data available for the new species are still insufficient to assess its conservation status. According to the IUCN Criteria (IUCN 2022), it is considered Data Deficient (DD) until more information becomes available. Although S. yanii currently has relatively good growth, further collection and monitoring are necessary to allow more conclusive estimations about the rarity and vulnerability of the species. Therefore, special attention should be given to the conservation of the new species of Spiradiclis.

Additional specimen

Longan • Southeast Guangxi: limestone hills, 7 November 2011, J.C. Yang&Y.B. Liao TK028 (IBK!); Longan, 14 March 2024 Y Nong NY2024031401 (GXMI!).

Figure 5. 

The distribution of Spiradiclis yanii (red circle) in Guangxi, China.

Acknowledgements

We are grateful to Xiang-chun Lan for fieldwork assistance and Xin-Cheng Qu for the line drawing (Guangxi Institute of Traditional Medical and Pharmaceutical Sciences, Nanning).

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 (32000264), the Survey and Collection of Germplasm Resources of Woody & Herbaceous Plants in Guangxi, China (GXFS–2021–34).

Author contributions

Data curation: YN. Funding acquisition: YN, CGX. Investigation: YN, CGX, YGW. Methodology: YN, LQL, YGW. Project administration: YN, ZYZ. Supervision: BF, LW. Visualisation: YN, LQL. Writing-original draft: YN. Writing-review and editing: YN

Author ORCIDs

You Nong https://orcid.org/0000-0001-7004-0946

Li-Qun Lei https://orcid.org/0009-0009-7319-5439

Gui-Yuan Wei https://orcid.org/0000-0003-0652-1213

Xin-Cheng Qu https://orcid.org/0009-0009-9078-9976

Zi-Yi Zhao https://orcid.org/0000-0003-2513-0728

Bin Feng https://orcid.org/0000-0003-0387-3635

Chuan-Gui Xu https://orcid.org/0009-0000-6263-3821

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.

References

  • Bremer B (2009) A review of molecular phylogenetic studies of Rubiaceae. Annals of the Missouri Botanical Garden 96(1): 4–26. https://doi.org/10.3417/2006197
  • Cai JH, Shui YM, Song XF, Wu L (2022) Validation of the name Spiradiclis elliptica (Rubiaceae), a new species endemic to southwestern China. Phytotaxa 545(1): 110–114. https://doi.org/10.11646/phytotaxa.545.1.10
  • Chen T, Taylor CM (2011) Spiradiclis. In: Wu ZY, Raven PH, Hong DY (Eds) Flora of China. Vol 19. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis, 330–339.
  • Darwin SP (1976) The Pacific species of Ophiorrhiza L. (Rubiaceae). Lyonia 1: 48–101.
  • Li JL, Yuan Q, Liu Y, Song XF, Pan B, Qu CH, Wu L (2021) Two new species of Spiradiclis (Rubiaceae) from limestone areas in southwestern China. Nordic Journal of Botany 39(2): e02979. https://doi.org/10.1111/njb.02979
  • Liu J, Pan B, Li SW, Xu WB (2017) Spiradiclis quanzhouensis (Rubiaceae): A new species from limestone area in Guangxi, China. Nordic Journal of Botany 36(3): e01595. https://doi.org/10.1111/njb.01595
  • Lo HS (1999) Spiradiclis Blume. In: Lo HS (Ed.) Flora Reipublicae Popularis Sinicae. Vol. 71(1). Science Press, Beijing, 86–110.
  • Lo HS, Sha WL, Chen XX (1983) A revision of the genus Spiradiclis Bl. Acta Botanica Austro Sinica 1: 27–36.
  • Pan B, Tu RH, Hareesh VS, Wu L (2019) Spiradiclis cavicola (Rubiaceae), a new species from limestone caves in south-western China. Annales Botanici Fennici 56(1–3): 1–4. https://doi.org/10.5735/085.056.0101
  • Razafimandimbison SG, Rydin C (2019) Molecular-based assessments of tribal and generic limits and relationships in Rubiaceae (Gentianales): Polyphyly of Pomazoteae and paraphyly of Ophiorrhizeae and Ophiorrhiza. Taxon 68(1): 72–79. https://doi.org/10.1002/tax.12023
  • Robbrecht E (1988) Tropical woody Rubiaceae. Opera Botanica Belgica 1: 1–271.
  • Robbrecht E (1993) Supplement to the 1988 outline of the classification of the Rubiaceae. Opera Botanica Belgica 6: 173–196.
  • Rydin C, Kainulainen K, Razafimandimbison SG, Smedmark JEE, Bremer B (2009) Deep divergences in the coffee family and the systematic position of Acranthera. Plant Systematics and Evolution 278(1–2): 101–123. https://doi.org/10.1007/s00606-008-0138-4
  • Song XF, Liu WJ, Chen AX, Yao ZM, Lan HB, Wu L (2022) Spiradiclis liboensis (Rubiaceae), a new species from limestone mountain areas in Guizhou, China. PhytoKeys 204: 73–81. https://doi.org/10.3897/phytokeys.204.84397
  • Verdcourt B (1958) Remarks on the calassification of the Rubiaceae. Bulletin van den Rijksplantentuin. Brussel 28: 209–281. https://doi.org/10.2307/3667090
  • Wen ZJ, Yang JC, Xu YF, Wu L (2019) Spiradiclis densa sp. nov. (Rubiaceae) from limestone areas in Guangxi, China. Nordic Journal of Botany 37(6): e02190. https://doi.org/10.1111/njb.02190
  • Wikström N, Neupane S, Kårehed J, Motley TJ, Bremer B (2013) Phylogeny of Hedyotis L. (Rubiaceae: Spermacoceae): redefining a complex Asian-Pacific assemblage. Taxon 62(2): 357–374. https://doi.org/10.12705/622.2
  • Wu L, Wang JL, Liu QR (2015) Spiradiclis pauciflora (Rubiaceae), a new species from limestone areas in Guangxi, China. Annales Botanici Fennici 52(3–4): 257–261. https://doi.org/10.5735/085.052.0318
  • Wu L, Tong Y, Pan B, Liu QR (2016) Spiradiclis glabra sp. nov. (Rubiaceae) from limestone areas in Guangdong, China. Nordic Journal of Botany 34(6): 718–721. https://doi.org/10.1111/njb.01156
  • Zhang F, Liu Y, Wen ZJ, Wu L (2018) Spiradiclis lui, a new species of Rubiaceae from Guangxi, China. Nordic Journal of Botany 36(6): e01786. https://doi.org/10.1111/njb.01786
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