Research Article
Print
Research Article
Paraboea zunyiensis (Gesneriaceae), a new species from north Guizhou, China
expand article infoTan Deng‡, Fang Wen§|, Da-Jun Xie, Ruo-Xun Wei‡, Lin He‡, Quan-Li Dou‡, Zheng-Min Qian‡, Ren-Bo Zhang‡
‡ Zunyi Normal College, Zunyi, China
§ Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences, Guilin, China
| National Gesneriaceae Germplasm Resources Bank of GXIB, Guilin, China
¶ Sichuan Academy of Forestry, Chengdu, China

Corresponding author: Ren-Bo Zhang ( ddzrb@126.com )

Academic editor: Bo Li
© 2023 Tan Deng, Fang Wen, Da-Jun Xie, Ruo-Xun Wei, Lin He, Quan-Li Dou, Zheng-Min Qian, Ren-Bo Zhang.
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: Deng T, Wen F, Xie D-J, Wei R-X, He L, Dou Q-L, Qian Z-M, Zhang R-B (2023) Paraboea zunyiensis (Gesneriaceae), a new species from north Guizhou, China. PhytoKeys 235: 21-29. https://doi.org/10.3897/phytokeys.235.111412
Open Access

Abstract

A new lithophytic species, Paraboea zunyiensis T.Deng, F.Wen & R.B.Zhang (Gesneriaceae), inhabiting Karst rocks in northern Guizhou, China, is introduced and depicted in this study. It bears a resemblance to P. crassifolia (Hemsl.) B.L. Burtt, yet is distinguishable by its shorter filaments and staminodes, triangular ovate calyx segments, and ovaries surpassing the styles in length. Moreover, the phylogenetic tree constructed from nuclear DNA (ITS) and plastid DNA (trnL-F) data firmly support the differentiation of this novel species from P. crassifolia.

Key words

Flora of Guizhou, lithophyte, new taxon, Paraboea crassifolia, taxonomy

Introduction

Paraboea (C.B.Clarke) Ridl. was first published by Clarke as a section, Didymocarpus sect. Paraboea Clarke (1883) (Xu et al. 2008), and was elevated to generic level by Ridley (1905). Burtt (1984) defined Boea and Paraboea based on differences in indumentum (simple straight hairs in Boea and interwoven arachnoid-like hairs in Paraboea). Paraboea comprises ca. 130 species characterized by abaxially matted leaves with densely interwoven indumentum and flowers featuring flat-faced to shortly campanulate corolla and non-erect anthers (Guo 2016; Xu et al. 2017). At present, this genus is a member of the tribe Didymoearpeae, subfamily Cyrtandroideae, family Gesneriaceae (Wang et al. 1990), and is primarily distributed in Karst habitats in China. Exceptions include Paraboea crassifila W.B.Xu & J.Guo (exclusively found in the Danxia landscape of Rong County, Guangxi, China) (Guo 2016) and P. sinensis (Oliv.) B.L.Burtt (found in both the Karst and Danxia landscapes) (Wei 2018; Wei et al. 2022).

Firstly, in China, Paraboea was initially recognized with 18 species, most of which exhibit narrow endemism (Wang et al. 1998; Fu et al. 2004). The southern region of China hosts a rich diversity of Paraboea species. Over ten new species have been reported since 2004 across various provinces: Guangxi (Xu and Wei 2004; Chen et al. 2008; Xu et al. 2012; Wen and Wei 2016), Guangdong (Wen et al. 2013; Wen and Wei 2016), Yunnan (Chen et al. 2012; He et al. 2018; Zhang et al. 2020), Hunan (Wen and Wei 2016), and Guizhou Province (Wen and Wei 2016; Guo et al. 2020).

In April 2023, a Paraboea-like species that was morphologically similar to P. crassifolia (Hemsl.) B.L.Burtt. was discovered in Guizhou Province, China. Through meticulous analysis of flowering specimens in the laboratory and detailed observation of live plants to compare vegetative and reproductive organs, significant distinctions between the two species became evident. The application of ITS and trnL-F for phylogenetic analysis further validated the distinctness of the new species from P. crassifolia. As a result, a conclusion was reached, designating it as a novel species within the realm of scientific understanding.

Materials and methods

Taxonomic revision

The studied specimens were obtained from the type locality and deposited in the Botany Herbarium at Zunyi Normal College (ZY) and the Guangxi Institute of Botany Herbarium (IBK). Using a stereomicroscope (Olympus Optical Microscope SZ61, Olympus Corporation, Japan), we conducted micromorphological analyses and photography. We compared the morphological traits with the protologue and type specimens of previously described Paraboea species, especially new Paraboea taxa from Guizhou and nearby provinces, along with herbarium specimens at relevant herbaria (e.g., IBK, IBSC, KUN, PE, and ZY).

Phylogenetic analysis

Leaf material of the undescribed species was collected in Maoli Town, Zunyi City (Guizhou, China) and promptly silica-dried for DNA extraction. The nuclear ribosomal internal transcribed spacer (ITS) region and plastid trnL-F intron spacer region (trnL-F) were utilized in the study. Following Weber et al. (2011), we employed primers, conducted DNA extraction, PCR amplification and sequencing. To elucidate the genus’s phylogenetic affinities, we integrated 36 Paraboea species (Table 1). Three former Boea species, Damrongia clarkeana (Hemsl.) C.Puglisi, Dorcoceras hygrometrica Bunge and Dorcoceras philippinense Schltr., were selected as outgroups based on prior phylogenetic analyses (Möller et al. 2011; Guo 2016).

Table 1.
Download as
CSV
XLSX

The GenBank accession numbers used in this study.

Species name ITS trnL-F
Damrongia clarkeana KJ475430 KM232645
Dorcoceras hygrometrica FJ501319 FJ501476
Dorcoceras philippensis HQ632953 HQ632862
Paraboea acutifolia JN934753 FJ501464
Paraboea amplifolia JN934754 JN934712
Paraboea burttii JN934756 JN934714
Paraboea capitata FJ501315 AJ492298
Paraboea clarkei JN934757 JN934715
Paraboea crassifolia KU203970 FJ501472
Paraboea dictyoneura KJ475415 FJ501463
Paraboea divaricata JN934759 JN934717
Paraboea effusa JN934760 JN934718
Paraboea glabra JN934761 JN934719
Paraboea glabrescens JN934785 JN934743
Paraboea glabrisepala JN934762 JN934720
Paraboea glanduliflora JN934763 JN934721
Paraboea glandulosa JN934784 JN934742
Paraboea glutinosa JN934764 JN934722
Paraboea hainanensis MF315101 MF315107
Paraboea harroviana var. ovata JN934765 JN934723
Paraboea havilandii JN934766 JN934724
Paraboea incudicarpa JN934767 JN934725
Paraboea martinii MF358702 MF358718
Paraboea neurophylla JN934769 JN934727
Paraboea paniculata JN934770 JN934728
Paraboea paramartinii JN934771 JN934729
Paraboea rufescens JN934772 FJ501469
Paraboea sinensis JN934773 FJ501474
Paraboea subplana JN934786 JN934744
Paraboea suffruticosa JN934774 JN934732
Paraboea swinhoei JN934775 JN934733
Paraboea tarutaoensis JN934776 JN934734
Paraboea trachyphylla JN934777 JN934735
Paraboea trisepala JN934778 JN934736
Paraboea umbellata JN934779 JN934737
Paraboea velutina JN934780 MF358725
Paraboea verticillata JN934781 JN934739
Paraboea vulpina JN934782 JN934740
Paraboea zunyiensis sp. nov. OR125066 OR123588

Bayesian inference was implemented using MrBayes v3.2.6. Prior to the Bayesian analysis, the mrModelTest v1.0 incorporating the Akaike information criterion (AIC) was used for selecting the best-fit molecular evolution model (GTR+I+G for the ITS and GTR for the trnL-F). Homogeneity testing was conducted via PAUP4 software (https://paup.phylosolutions.com/) yielding a p value < 0.05, thus prompting the merger of the two regions for subsequent analyses. The BI analyses entailed four Markov Chain Monte Carlo (MCMC) chains, with tree sampling every 100 generations for 2,000,000 generations from a random tree. Upon stabilizing log-likelihood scores, a consensus tree was computed, excluding 5,000 sampled trees as burn-in (Xie et al. 2014). Tree visualization was carried out in FigTree v.1.4.3 (http://tree.bio.ed.ac.uk/software/figtree/).

Taxonomic treatment

Paraboea zunyiensis T.Deng, F.Wen & R.B.Zhang, sp. nov.

urn:lsid:ipni.org:names:77330011-1
Figs 1, 2

Diagnosis

Paraboea zunyiensis morphologically resembles P. crassifolia, but can be distinguished by the shorter staminodes (< 1 mm vs. 2–2.5 mm in P. crassifolia, following the same order), filaments (ca. 1 mm vs. (3–) 5.5–7 mm) and anthers (1.5–2.3 mm vs. 2.5–3 mm), calyx lobe shape (triangular ovate vs. narrowly triangular to linear), the outer calyx indumentum (tomentose vs. puberulent or velutinous), and the ovary length (ovaries longer than the styles vs. ovaries shorter than the styles).

Figure 1. 

Line drawing of Paraboea zunyiensis T.Deng, F.Wen & R.B.Zhang, sp. nov. A flowering plant B corolla C opened corolla D adaxial leaf surface E abaxial leaf surface F calyx G bracts H pistil I capsules J seed K fertile stamens L staminodes. Drawings by Tan Deng from the type specimens.

Type

China, Guizhou Province, Zunyi City, Maoli Town, Xiazhai Valley, elev. ca. 1000 m, 27.36986425°N, 107.05679454°E, growing on the Karst rocks alongside the stream. 15 April 2023, Ren-Bo Zhang ZRB2493 (fl.) (holotype: IBK!, isotypes: ZY!) and 27 May 2023 Ren-Bo Zhang ZRB2498 (fr.) (paratype: ZY!).

Figure 2. 

Living or re-watered photographs of Paraboea zunyiensis T.Deng, F.Wen & R.B.Zhang, sp. nov. A habitat B flowering plant C cyme D flowers E fruiting plant F upward view of the plant G pistil H stigma and style I fertile stamens J staminodes K calyx L bracts M capsules N seeds (Photographed by T. Deng and R.B. Zhang)

Description

Herbs , stemless. Leaves basal, petiole 0.8–1.5 cm long; leaf blade spathulate or oboval-oblong, 3.5–12 (–25) × 1–3.5 (–8) cm, thick papery to leathery, adaxially cobwebby-woolly, glabrescent, abaxially densely cobwebby-woolly to pannose, base attenuate to cuneate, margin crenate or subentire, involute, apex rounded or acute; lateral veins 4–7 on each side of midrib. Cymes 1–2, axillary, each cyme 3–7 branched and 9–22 flowered; peduncle 2–6 cm long, ca. 1.5 mm in diam, cobwebby-woolly, glabrescent from upper part; bracts 2, opposite, linear, 2–3 × 0.6–0.9 mm, outside cobwebby-woolly. Pedicel 1–2 cm long, cobwebby-woolly. Calyx ca. 3 mm long, 5-sect from near base; segments triangular ovate, 1–2 × ca. 0.5 mm, outside brown tomentose. Corolla blue-purplish, ca. 1.5 cm long, subglabrous on both sides; tube 7–8 mm long; adaxial lip ca. 3 mm long, lobes 2–3 × ca. 5 mm; abaxial lip ca. 7 mm long, lobes 3–4 × 5–6 mm. Stamens 2, filaments ca. 1 mm long, glabrous; anthers 1.5–2.5 mm long; staminodes 2, ca. 0.8 mm long. Pistil glabrous; ovary 4–6 mm long; style 3–5 mm long; stigma capitate. Capsule spirally twisted, 2–4 cm long, glabrous. Seeds 0.5–0.7 × 0.2–0.3 mm, reticulate, apiculate or cuspidate at both ends. Fl. Apr–May. Fr. May–Jun.

Phenology

Flowering occurs from April to May, and fruiting occurs from May to June.

Etymology

The specific epithet is derived from the type locality, Zunyi City, Guizhou Province, China.

Vernacular name

The Chinese name proposed here is “遵义蛛毛苣苔”. Phonetically, it is “Zūn yì zhū máo jù tái”.

Distribution and ecology

The new species is endemic to Guizhou Province and is known only from the type locality, Xiazhai Valley in Zunyi City. It grows on the steep Karst cliff in a valley, at an altitude ca. 1000 m.

Conservation status

Paraboea zunyiensis is known only from the type locality, with the individuals estimated to be over thousands of plants. Considering the narrow distribution area, we proposed it as “NT” (near threatened) according to the guidelines for using the IUCN Red List Categories and Criteria (IUCN Standards and Petitions Committee 2022).

Taxonomic and phylogenetic notes

The aligned matrix of ITS and trnL-F sequences comprised 1562 characters. The three outgroup species are clearly distinguishable from the Paraboea species (Fig. 3). P. hainanensis (Chun) B.L.Burtt is quite different and other Paraboea species form two big clades, which matches a previous study (Guo 2016). Although P. zunyiensis and P. crassifolia are in the same branch (BI = 100%), they are not clustered together and they can be morphologically distinguished from the traits presented in Table 2. P. zunyiensis is clustered with P. neurophylla (Hance) B.L.Burtt and P. trisepala W.H.Chen & Y.M.Shui (BI = 100%). P. crassifolia and P. velutina (W.T.Wang & C.Z.Gao) B.L.Burtt are clustered as a sister group (BI = 95%) and then clustered with P. dictyoneura (Hance) B.L.Burtt.

Figure 3. 

Bayesian phylogenetic tree of Paraboea including P. zunyiensis based on the combined data from ITS and trnL-F, with the branch lengths indicating the nucleotide substitution rates and the posterior probabilities are shown beside the branches.

Table 2.
Download as
CSV
XLSX

Morphological and phenological comparison of Paraboea zunyiensis and P. crassifolia.

Characters Paraboea zunyiensis Paraboea crassifolia
Bract width (mm) 0.6–0.9 ca. 0.5
Calyx lobes triangular ovate narrowly triangular to linear
Calyx outer indumentum tomentose puberulent or velutinous
Filament length (mm) ca. 1 (3–) 5.5–7
Anther length (mm) 1.5–2.3 2.5–3
Staminode length (mm) < 1 2–2.5
Ovary (mm) 4–6 (longer than styles) 3–4 (shorter than styles)
Style (mm) 3–5 5.5–6
Fl. Apr–May Mar–Jul
Fr. May–Jun Sep

Additional information

Conflict of interest

The authors have declared that no competing interests exist.

Ethical statement

No ethical statement was reported.

Funding

This study was financially supported by the National Natural Science Foundation of China (31860162) and the Doctor Foundation of Zunyi Normal College (BS[2018]17).

Author contributions

Conceptualization: FW. Data curation: QLD, DJX. Formal analysis: QLD. Investigation: TD, RBZ. Resources: LH. Software: ZMQ, RXW. Supervision: FW. Visualization: RXW, TD. Writing - original draft: LH, RBZ, TD. Writing - review and editing: FW.

Author ORCIDs

Tan Deng https://orcid.org/0000-0002-4575-3298

Fang Wen https://orcid.org/0000-0002-3889-8835

Da-Jun Xie https://orcid.org/0009-0008-4030-4718

Ruo-Xun Wei https://orcid.org/0009-0000-0510-7470

Lin He https://orcid.org/0009-0000-9952-7475

Quan-Li Dou https://orcid.org/0009-0003-8462-7774

Zheng-Min Qian https://orcid.org/0009-0006-7721-966X

Ren-Bo Zhang https://orcid.org/0000-0002-9860-5803

Data availability

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

References

  • Burtt BL (1984) Studies in the Gesneriaceae of the Old World: XLVII - Revised generic concepts for Boea and its allies. Notes from the Royal Botanic Garden Edinburgh 41: 401–452.
  • Chen WH, Moller M, Shui YM, Zhang MD (2008) A new species of Paraboea (Gesneriaceae) from a karst cave in Guangxi, China, and observations on variations in flower and inflorescence architecture. Botanical Journal of the Linnean Society 158(4): 681–688. https://doi.org/10.1111/j.1095-8339.2008.00873.x
  • Chen WH, Möller M, Zhang MD, Shui YM (2012) Paraboea hekouensis and P. manhaoensis, two new species of Gesneriaceae from China. Annales Botanici Fennici 49(3): 179–187. https://doi.org/10.5735/085.049.0304
  • Clarke CB (1883) Cyrtandreae. In: De Candolle A, De Candolle C (Eds) Monographie Phanerogamarum (Vol. 5), 1–303.
  • Fu LG, Chen TQ, Lang KY, Hong T, Lin Q, Li Y (2004) Higher Plants of China (Vol. 10). Qingdao Press, Qingdao.
  • Guo J (2016) A Systematic Study on the Genus Paraboea (Gesneriaceae) in China. Master Thesis, Guangxi Normal University, China.
  • Möller M, Forrest A, Wei YG, Weber A (2011) A molecular phylogenetic assessment of the advanced Asiatic and Malesian didymocarpoid Gesneriaceae with focus on non-monophyletic and monotypic genera. Plant Systematics and Evolution 292(3–4): 223–248. https://doi.org/10.1007/s00606-010-0413-z
  • Ridley HN (1905) The Gesneriaceae of the Malay Peninsula. Journal of the Straits Branch of the Royal Asiatic Society 43: 1–92.
  • Wang WT, Pan KY, Li ZY (1990) Gesneriaceae. In: Wang WT (Ed.) Flora Reipublicae Popularis Sinicae (Vol. 69). Science Press, Beijing.
  • Wang WT, Pan KY, Li ZY, Weitzman AL, Skog LE (1998) Generiaceae. In: Wu ZY, Raven PH (Eds) Flora of China (Vol. 18). Science Press & Missouri Botanical Garden Press, Beijing & St. Louis, 244–401.
  • Wei YG (2018) The Distribution and Conservation Status of Native Plants in Guangxi, China. China Forestry Publishing House, Beijing.
  • Wei YG, Do VT, Wen F (2022) A checklist to the plants of northern Vietnam. China Forestry Publishing House, Beijing.
  • Wen F, Wei YG (2016) Paraboea yunfuensis: A new calcicolous species of Gesneriaceae from Yunfu, Guangdong Province, China. Telopea Journal of Plant Systematics 19: 125–129. https://doi.org/10.7751/telopea10316
  • Wen F, Hong X, Chen LY, Zhou SB, Wei YG (2013) A new species of Paraboea (Gesneriaceae) from a karst limestone hill in southwestern Guangdong, China. Phytotaxa 131(1): 1–8. https://doi.org/10.11646/phytotaxa.131.1.1
  • Xie DM, Peng DY, Fang CW, Qin MJ, Wang DQ, Huang LQ (2014) Sedum spiralifolium (Crassulaceae): A new species from Anhui Province, China. Phytotaxa 183(3): 171–182. https://doi.org/10.11646/phytotaxa.183.3.4
  • Xu L, Wei YG (2004) Paraboea guilinensis L. Xu & Y. G. Wei, a new species of Gesneria­ceae from Guangxi, China. Zhiwu Fenlei Xuebao 42: 380–382.
  • Xu WB, Huang YS, Wei GF, Tan WN, Liu Y (2012) Paraboea angustifolia (Gesneriaceae): A new species from limestone areas in northern Guangxi, China. Phytotaxa 62(1): 39–43. https://doi.org/10.11646/phytotaxa.62.1.8
  • Xu WB, Guo J, Pan B, Han MQ, Liu Y, Chung KF (2017) Three new species of Paraboea (Gesneriaceae) from limestone karsts of China based on morphological and molecular evidence. Botanical Studies 58(1): 56. https://doi.org/10.1186/s40529-017-0207-5
  • Zhang GL, Cai L, Wang YZ, Zhang GS (2020) Paraboea nanxiensis (Gesneriaceae), a new species from southeastern Yunnan Province, China. Guihaia 40: 1423–1428.
login to comment