Primula xinjingensis (Primulaceae), a new species from Guizhou, China

223 Primula xinjingensis (Primulaceae), a new species from Guizhou, China Sheng-Hu Tang1, Ze-Xu Long2, Fang-Wen Li3 1 Gesneriad Conservation Center of China (Guizhou), National Forestry and Grassland Administration Key Laboratory for Biodiversity Conservation in Karst Terrain of Southwestern China, Guizhou Botanical Garden, Guiyang 550000, China 2 School of Biological Science, Guizhou Educational University, Guiyang 550000, China 3 Chengdu Botanical Garden (Chengdu Park City Botanical Science Research Institute), Chengdu 610000, China Corresponding author: Fang-Wen Li ([email protected]) Copyright: © Sheng-Hu Tang 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 A new species, named Primula xinjingensis, has been described from north-eastern Guizhou, China. It belongs to the sect. Monocarpicae. The species resembles P. pellucida in having efarinose plants, the shape of the leaf blade, and recurved calyx lobes in fruit. However, it differs from P. pellucida by possessing a campanulate calyx, lanceolate calyx lobes, narrowly cuneate-obovate corolla limb lobes, and a style reaching the throat in the pin flowers. It also shares similarities with P. divaricata and P. epilithica in terms of efarinose plants and the shape of the leaf blade. Nevertheless, it is distinct from these two species by the absence of rhizomes, having recurved calyx lobes in fruit, lanceolate calyx lobes, and narrowly cuneate-obovate corolla limb lobes. The new taxon has been assessed as “Data Deficient” (DD) according to the IUCN standards. Key words: karst flora, new taxon, Primula, Yanhe County Introduction Primula L. is a large genus belonging to the family Primulaceae, comprising approximately 548 species worldwide (POWO 2025). This genus primarily occurs in the temperate and alpine regions of the Northern Hemisphere (Hu 1990; Hu and Kelso 1996). In China, approximately 351 species have been documented (Liu 2025). In recent years, numerous new taxa have been discovered in China (IPNI 2025), including P. yanbianensis T.Shuai, Lei Cai & Z.K.Wu (Shuai et al. 2025), P. medogensis W.B.Ju, Bo Xu & X.F.Gao (Ju et al. 2023), P. zhengyii Bin Yang & Y.H.Tan (Yang et al. 2023), and P. xinningensis Wei Zhang bis & J.W.Shao (Zhang et al. 2022). The section Monocarpicae Franch. ex Pax of the genus Primula is characterized by plants having multicellular hairs, membranous leaves with a distinct petiole and a round or heart-shaped blade base, a campanulate calyx, and a globose or cylindrical capsule dehiscing by valves (Hu 1990). This section is a small group consisting of 21 species in China (Hu and Kelso 1996; Xu et al. 2016a, 2016b, 2017, 2022). During a field survey conducted in March 2025 in Yanhe County, Guizhou Province, China, we discovered some flowering plants belonging to the genus Primula. In April 2025, we returned to collect specimens and take photographs. Academic editor: Avelinah Julius Received: 7 August 2025 Accepted: 23 September 2025 Published: 4 November 2025 Citation: Tang S-H, Long Z-X, Li F-W (2025) Primula xinjingensis (Primulaceae), a new species from Guizhou, China. PhytoKeys 265: 223–232. https://doi.org/10.3897/ phytokeys.265.168043 PhytoKeys 265: 223–232 (2025) DOI: 10.3897/phytokeys.265.168043 224 PhytoKeys 265: 223–232 (2025), DOI: 10.3897/phytokeys.265.168043 Sheng-Hu Tang et al.: Primula xinjingensis In June 2025, we harvested the capsules from the plants cultivated at the Guizhou Botanical Garden. The plants are characterized as perennial, efarinose herbs lacking rhizomes. They feature a 5–9-lobulate leaf blade with multicellular hairs, lanceolate calyx lobes that are recurved in fruits, and narrowly cuneate-obovate corolla lobes. After thorough comparisons, we concluded that they represent a new species belonging to the section Monocarpicae. Materials and methods The morphological characteristics of approximately 100 mature individuals were observed, and 20 selected flowers were carefully observed and measured in the field. A microscope (Olympus SZ61, Tokyo, Japan) was used for micro-observation. The plant was described following the terminology used by Hu and Kelso (1996). All the species belonging to the section Monocarpicae in China have been examined using type specimens or the descriptions provided by Hu (1990) and Hu and Kelso (1996). Relevant literature was consulted, including Xu et al. (2016a, 2016b, 2017, 2022). The relevant images were sourced from virtual herbaria and databases, including E (https://data.rbge.org.uk/search/herbarium/), P (https:// science.mnhn.fr/all/search), iPlant (http://www.iplant.cn/), and CVH (https://www. cvh.ac.cn/), CFH (https://www.cfh.ac.cn/) and CUBG (https://image.cubg.cn/). Taxonomic treatment Primula xinjingensis Sheng H.Tang & F.W.Li, sp. nov. urn:lsid:ipni.org:names:77371343-1 Figs 1–3 Diagnosis. The new species bears a striking resemblance to Primula pellucida Franch. in terms of the efarinose plants, the shape of the leaf blade, and the recurved calyx lobes in fruit. However, it is distinguished by having a campanulate (vs. broadly campanulate) calyx, lanceolate (triangular to ovate) calyx lobes, narrowly cuneate-obovate (vs. obovate) corolla limb lobes and a style reaching the throat (vs. exserted from the corolla tube) in the pin flowers. The new species also shares similarities with P. divaricata F. H.Chen & C.M.Hu and P. epilithica F.H.Chen & C.M.Hu in terms of leaf blade size and shape, as well as the campanulate calyx. Nevertheless, it is set apart from these two species by the absence of rhizomes (vs. their presence), lanceolate (vs. triangular or ovate-triangular) calyx lobes that are recurved (vs. erect) in fruits, and narrowly cuneate-obovate (vs. cuneate-obovate or obovate) corolla limb lobes. Type. China. Guizhou Province: Yanhe County, Xinjing Town, 28°52'N, 108°18'E, ca. 700 m, 3 April 2025, Sheng H.Tang & Da-Zhu Tang 202504001 (holotype: CSH! [accession number CSH0220070]; isotype: the Guizhou Botanical Garden!). Description. Herbs perennial, efarinose, without rhizomes, up to 9 cm tall at anthesis. Roots numerous, fibrous. Leaves 7–20, forming a rosette; petiole 5–13 mm long, short-stalked glandular and sparsely multicellular hairs; leaf blade ovate or suborbicular, 4–12 × 4–10 mm, membranous when dry, abaxially and adaxially with multicellular hairs, base cordate, apex acute, margin 5–9-lobulate; lobules ovate to broadly ovate, margin entire, some- 225 PhytoKeys 265: 223–232 (2025), DOI: 10.3897/phytokeys.265.168043 Sheng-Hu Tang et al.: Primula xinjingensis Figure 1. Primula xinjingensis sp. nov. A. Flowering plant, and bracts (inset); B. Adaxial and abaxial surfaces of the leaf blade, and multicellular hairs on both sides (inset); C, D, E. Pin flower; F, G, H, I, J. Thrum flower; K, L. Capsules; M. Seeds. Photographs by Sheng-Hu Tang. 226 PhytoKeys 265: 223–232 (2025), DOI: 10.3897/phytokeys.265.168043 Sheng-Hu Tang et al.: Primula xinjingensis times with 1 or 2 teeth, apex acute; lateral veins 3–4 pairs, obscure adaxially and prominent abaxially. Scapes 1–3, short-stalked glandular and sparsely multicellular hairs, 1–4 cm tall, umbel 1, rarely 2, 1–4-flowered; bracts 3, sometimes 2 or 4, linear-lanceolate, 2–3 mm long, short-stalked glandular on both sides. Flowers heterostylous. Pedicel 1–2 cm long, short-stalked glandular and sparsely multicellular hairs. Calyx campanulate, 2–4 mm long, slightly enlarged in fruit, short-stalked glandular and sparsely multicellular hairs outside, glabrous inside, parted to middle or slightly below; lobes 1.5–2.5 × 0.8–0.9 mm, lanceolate, recurved at anthesis sometimes, and recurved in fruit, apex acuminate. Corolla rose-purple; tube 6–9 mm long; limb 9–14 mm wide; lobes 4–6 mm long, narrowly cuneate-obovate, deeply emarginate. Pin flowers: stamens 2–2.2 mm above base of corolla tube, style 4.5–7 mm long, reaching throat. Thrum flowers: stamens toward Figure 2. Habitats of Primula xinjingensis sp. nov. (Population at the type locality). Photographs by Sheng-Hu Tang. 227 PhytoKeys 265: 223–232 (2025), DOI: 10.3897/phytokeys.265.168043 Sheng-Hu Tang et al.: Primula xinjingensis Figure 3. Holotype of Primula xinjingensis sp. nov. stored in CSH (Sheng H.Tang & Da-Zhu Tang 202504001, CSH0220070). 228 PhytoKeys 265: 223–232 (2025), DOI: 10.3897/phytokeys.265.168043 Sheng-Hu Tang et al.: Primula xinjingensis apex of corolla tube, style 2.5–3 mm long. Capsule globose, 1.7–2.1 mm in diam., dehiscing by 2 valves or crumbling irregularly. Seeds numerous, ovoid or irregularly ovoid, 0.5–0.8 mm long, brown, testa reticulate. Phenology. Flowering occurs from late March to early April, and fruiting occurs from May to June. Etymology. The new taxon was named for its locality, Xinjing Town, Yanhe County, Guizhou Province, China. Vernacular name. The Chinese name is “Xīn Jǐng Bào Chūn” (新景报春). Distribution and habitat. Only one population was discovered in Xinjing Town, Yanhe County, Guizhou Province, China (Fig. 4). It thrives on moist, shady cliffs and limestone surfaces. The primary companion species are Androsace kouytchensis Bonati, Petrocodon scopulorum (Chun) Yin Z.Wang, and Ophiorrhiza chinensis H.S.Lo. Conservation status. Only one population, consisting of approximately 200 mature individuals, was discovered at the type locality. Additional populations likely exist in this area. Until further investigation is conducted, the species should be designated as “Data Deficient” (DD) in accordance with the IUCN Red List Criteria (IUCN 2024). Notes. The new species bears the closest resemblance to Primula pellucida (Fig. 5), P. divaricata (Fig. 6), and P. epilithica (Fig. 6), and we have successfully obtained images of their type specimens. The detailed morphological comparison is shown in Table 1, as well as an identification key to P. xinjingensis and its related species. Figure 4. Location of the population of Primula xinjingensis sp. nov. in Yanhe County, Guizhou Province, China (indicated by the blue circle). 229 PhytoKeys 265: 223–232 (2025), DOI: 10.3897/phytokeys.265.168043 Sheng-Hu Tang et al.: Primula xinjingensis Figure 5. The type specimen of Primula pellucida stored in P (Delavay 2274, P04544677). 230 PhytoKeys 265: 223–232 (2025), DOI: 10.3897/phytokeys.265.168043 Sheng-Hu Tang et al.: Primula xinjingensis Key to Primula xinjingensis and its related species 1 Inflorescences and abaxial surface of leaves more or less farinose ........2 – Plants efarinose throughout .........................................................................3 2 Calyx parted below middle, lobes lanceolate to linear-lanceolate ............... .......................................................................................................P. duclouxii – Calyx parted to the middle, lobes triangular to narrowly triangular ............. .....................................................................................................P. petrocallis Table 1. Detailed comparisons among Primula xinjingensis, P. pellucida, P. divaricata and P. epilithica. Characters P. xinjingensis P. pellucida P. divaricata P. epilithica Habitat alt. ca. 700 m alt. ca. 2000 m alt. 1800–2700 m alt. 2300–2500 m Rhizomes absent absent present present Calyx Calyx shape campanulate broadly campanulate campanulate campanulate Lobe shape lanceolate triangular to ovate triangular ovate-triangular Lobe apex acuminate acute acute acute Lobes in fruit recurved recurved erect erect Corolla limb lobes narrowly cuneate-obovate obovate cuneate-obovate obovate Pin flowers style reaching throat style exserted from corolla tube style ca. as long as tube style reaching throat Figure 6. The type specimens of Primula divaricata and P. epilithica. A. Isotype of P. divaricata stored in WUK (M.K.Li 3439, 271331); B. Holotype of P. epilithica stored in KUN (M.K.Li 1199, 1218844). 231 PhytoKeys 265: 223–232 (2025), DOI: 10.3897/phytokeys.265.168043 Sheng-Hu Tang et al.: Primula xinjingensis 3 Rhizomes absent, calyx lobes recurved in fruits .........................................4 – Rhizomes present, calyx lobes erect in fruits ..............................................5 4 Calyx campanulate, and style of pin flowers reaching throat ...................... .................................................................................................. P. xinjingensis – Calyx broadly campanulate, and style of pin flowers exserted .................... .......................................................................................................P. pellucida 5 Scapes with small leaves at apex; calyx 2–3 mm .....................P. divaricata – Scapes without leaves at apex; calyx ca. 4 mm ......................... P. epilithica Acknowledgements Thanks to E (https://data.rbge.org.uk/search/herbarium/), P (https://science. mnhn.fr/all/search), iPlant (http://www.iplant.cn/), CVH (https://www.cvh. ac.cn/), CFH (https://www.cfh.ac.cn/), and CUBG (https://image.cubg.cn/) for providing a wealth of relevant images on the Internet. Thanks to P and CVH for granting us permission to use their images for this publication. The MNHN gives access to the collections in the framework of the RECOLNAT international Research Infrastructure. We are grateful to Da-Zhu Tang, Yue-Heng Feng and Jia-Hao Fang for their kind contributions to the field work, and to Bin-Jie Ge for depositing the type specimen of the new taxon in CSH. 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 work was supported by the National Natural Science Foundation of China (32160095), the Guizhou Botanical Garden (Z[2023]01), the Guizhou Provincial Basic Research Program (Natural Science): No. Qian-Ke-He-Ji-Chu [2023]1Y235, and the Central Forestry and Grassland Ecological Protection and Restoration Fund (MYH2024-HT041). Author contributions Sheng-Hu Tang and Fang-Wen Li conceived the study. Sheng-Hu Tang and Ze-Xu Long collected the samples. Sheng-Hu Tang, Ze-Xu Long, and Fang-Wen Li conducted the measurements of the morphological characteristics, data analysis, and microscopic observations. Sheng-Hu Tang and Ze-Xu Long wrote the original manuscript. Fang-Wen Li reviewed and edited the manuscript. All the authors approved the final version of the manuscript. Author ORCIDs Sheng-Hu Tang https://orcid.org/0000-0002-2168-8559 Ze-Xu Long https://orcid.org/0000-0002-2870-8751 Fang-Wen Li https://orcid.org/0009-0002-6326-5922