Research Article |
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Corresponding author: Xiao-Feng Jin ( docxfjin@163.com ) Academic editor: Pedro Jiménez-Mejías
© 2025 Yi-Fei Lu, De-Chang Meng, Xiao-Feng Jin.
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:
Lu Y-F, Meng D-C, Jin X-F (2025) Carex yangchunensis, a new species of Cyperaceae from the limestone regions of Guangdong, South China. PhytoKeys 251: 257-270. https://doi.org/10.3897/phytokeys.251.142179
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Carex yangchunensis (Cyperaceae), a new species of Carex sect. Cryptostachyae in limestone regions of Guangdong, China, is described and illustrated. Both morphological observation and molecular analysis revealed that the new species was similar to C. cryptostachys, but differs in having inflorescence with 4–8 spikes, ovoid or nearly globose, 3–8 mm long, utricles (2.5–3.5 mm long) and nutlets (2–2.2 mm long) shorter, style base thickened, leaves narrower, 3–6 mm wide and culms 8–25 cm tall. Scanning electron micromorphology of utricles and nutlets of the new species and the related species C. cryptostachys are provided.
Carex sect. Cryptostachyae, Carex yangchunensis, Cyperaceae, micromorphology, phylogeny, taxonomy
The Cyperaceae, a family of grass-like plants containing 5600+ species in 95 genera, is the third largest family amongst monocots following the Orchidaceae and Poaceae (
Phylogenetic analyses, based on DNA sequences, have been increasingly applied in this century, as well as to the systematics of Carex, leading to a profound re-evaluation of its classification and subgeneric divisions. The phylogenetic studies revealed that all the other subgenera within Carex are polyphyletic, except subg. Vignea, which indicated that the traditional definition of the genus is polyphyletic and several smaller genera (Cymophyllus Mack., Kobresia Willd., Schoenoxiphium Nees and Uncinia Pers.) within trib. Carieae are nested within the branches of Carex (
Carex sect. Cryptostachyae comprises only one species, C. cryptostachys, which was established by
During a botanical exploration in the limestone regions of Guangdong Province in southern China, we collected a plant closely resembling Carex cryptostachys, which grows on limestone and has ovoid or nearly globose spikes. Based on morphological comparison and phylogenetic analysis, we confirm it as a new species and described it below.
Morphological characteristics of the new species were based both on studies of specimens and field trips. We focused on the shape of utricles and nutlets, inflorescence and spikes, which demonstrated that these specimens were similar to Carex cryptostachys. Herbarium specimens (including all type specimens) of sections Cryptostachyae, Lageniformes and Mitratae were examined at the following herbaria: BM, E, IBK, IBSC, K, KUN, KYO, P, PE, TI and ZJFC.
Scanning electron microscope (SEM) observations of utricles and nutlets of the new species and the similar species Carex cryptostachys were conducted. Mature utricles and nutlets were gathered from specimens, including X.F. Jin & Y.F. Lu 5196 for the new species and X. F. Jin & al. 2992 for C. cryptostachys. The utricles were submerged in 50% ethanol to clean them for 2 h. The nutlets were initially soaked in a solution of concentrated sulphuric acid and acetic anhydride (volume ratio = 1:9) for 12 hours, then rinsed in acetic acid for 10 min and water for 5 min; next, they were placed in a bath-type ultrasonic cleaner for 7 min with 70% ethanol to remove the cuticle and outer periclinal wall of the epidermis. After air drying, the cleaned utricles and nutlets were mounted on stubs by doubled-sided adhesive tape and coated with gold; next, they were observed and photographed under a Gemini-300 scanning electron microscope (Zeiss, Jena, Germany) (
A total of 146 species (including infraspecies) representing 58 clades or sections proposed by
Total genomic DNA was extracted from silica-dried leaves using Plant Genomic DNA Kit (Tiangen Biotech Co., Ltd., Beijing, China). Two nuclear DNA markers (ETS and ITS) and three plastid DNA markers (matK, rpl32-trnL(UAG) and trnL-F) were selected to amplification. Sequence amplification was conducted following
Sequences were assembled using SeqMan in DNASTAR Lasergene v.8.1.3 (
A total of 149 sheets/specimens of Carex cryptostachys from south China, Southeast Asia, South Asia to Australia were deposited in the above-mentioned herbaria and were available for measurement and a comparison of morphological characters. The morphological characters of C. cryptostachys showed considerable stability, but quite different from the new species in the characters listed in Table
Comparison of morphological characters of Carex cryptostachys and the new species.
| Character | Carex cryptostachys | C. yangchunensis sp. nov. |
|---|---|---|
| Culm height | 10–35 cm | 8–25 cm |
| Leaf width | 6–16 mm | 3–6 mm |
| Spike | ||
| Number | 6–10 | 4–8 |
| Shape | Cylindrical | Ovoid or globose |
| Length | 9–25 mm | 3–8 mm |
| Utricle | ||
| Length | 3.5–4.5 mm | 2.5–3.5 mm |
| Beak length | ca. 0.5 mm | ca. 0.3 mm |
| Nutlet | ||
| Length | 2.5–3 mm | 2–2.2 mm |
| Style base | Not thickened | Thickened |
Under a SEM, the utricles of the new species are broadly rhombic-obovoid, obtusely compressed-trigonous, dorsally glabrous and densely pubescent at the margin, with many longitudinally veins and beak orifice 2-lobed with minute teeth (Fig.
Micromorphology of utricles and nutlets of Carex yangchunensis sp. nov, (A–E) and Carex cryptostachys (F–J). A–C, F–H utricles D, E, I, J nutlets A, D, F, I overview B, G utricle and nutlet surface, respectively C, H beak E, J utricle and nutlet surface sculpture, respectively. Scale bars: 200 μm (A, D, F, I); 50 μm (B, J); 100 μm (C, H); 10 μm (E)
The nutlets of the new species and C. cryptostachys are both rhombic-obovoid, dorsally flat and ventrally concaved above and below. The epidermal cells of the nutlets of the new species are slightly concaved, while those of C. cryptostachys are convex with one silica body (Fig.
The lengths of five aligned sequences are: ETS 714 bp, ITS 749 bp, matK 805 bp, rpl32trnL(UAG) 1035 bp and trnL-F 1134 bp. The GTR+I+G model was the best for ETS and ITS and the GTR model for matK, rpl32-trnL(UAG) and trnL-F. The topology between the Bayesian Inference and Maximum Likelihood trees did not involve incongruences at the node with Bayesian posterior probability (PP) > 0.75 or bootstrap values (BS) > 50%. Similar to previous studies, the deep relationships amongst clades remain unresolved, with PP < 0.75 and BS < 50%. The three samples of the new species, C. yangchunensis, formed a strongly supported clade (PP = 1, BS = 100%) and showed a sister relationship with the morphologically closest species, C. cryptostachys (Fig.
This new species is similar to Carex cryptostachys Brongn., but differs in having spikes 4–8, ovoid or nearly globose, 3–8 mm long (vs. spikes 6–10, cylindrical, 9–25 mm long), utricles 2.5–3.5 mm long (vs. 3.5–4.5 mm long), nutlets 2–2.2 mm long, with styles thickened at base (vs. 2.5–3 mm long, style base not thickened), leaves 3–6 mm wide (vs. 6–16 mm wide) and culms 8–25 cm tall (vs. 10–35 cm tall).
China, Guangdong (广东), Yangchun County (阳春), Kongdongyan Scenic Spot (崆峒岩景区), from Banshanting to Zhaixingting (半山亭至摘星亭), 22.18544°N, 111.74557°E, elev. 80 m, 9 April 2024, X. F. Jin & Y. F. Lu 5196 (holotype: ZJFC!; isotypes: IBK!, PE!, ZJFC!, ZM!).
Perennial herbs. Rhizomes elongate, woody, thick. Culms lateral, 8–25 cm tall, compressed-trigonous, slender, smooth, base with dark-brown or brown sheaths, sometimes splitting into fibres. Leaves far longer than culms, apex slender long-caudate; blades 3–6 mm wide, thinly leathery, flat, upper margins and both surfaces scabrous. Bracts short-setaceous, sheathed; sheaths 3–10 mm long, with the most proximal one longer than the others. Spikes 4–8, androgynous, ovoid or nearly globose, 3–8 mm long, base with a 3–17 mm long slender peduncle, staminate part ca. 2 mm long, slightly exserted or hidden in pistillate flowers, pistillate part 3–6 mm long, densely 4–12-flowered; peduncles exserted from bract sheaths. Staminate glumes ovate, 1.5–2 mm long, yellow-white, obtuse at apex, green 3-veined dorsal costa. Pistillate glumes obovate or ovate, 2–2.5 mm long, pale yellow-green, acute or obtuse at apex, green 3-veined dorsal costa. Utricles yellow-green, broadly rhombic-obovoid (excluding beak), obtusely compressed-trigonous, 2.5–3.5 mm long (including beak), longer than pistillate glumes, yellow-green, membranous, distinctly thinly veined, sparsely pubescent on upper dorsal surface and margins, densely pubescent on ventral surface, base cuneate and narrowed into a ca. 0.5 mm long stipe, apex gradually contracted into a ca. 0.3 mm long beak, orifice 2-lobed with minute teeth. Nutlets tightly enveloped, rhombic-ovoid, trigonous, yellow, 2–2.2 mm long, with 3 angles constricted at middle, sides concave above and below, base with a 0.3–0.7 mm long stipe; style thickened at base, persistent, coiled; stigmas 3.
Photos of Carex yangchunensis sp. nov. (A–I) and Carex cryptostachys (J, K) A, B habitat C, J habit D lower part of habit, showing rhizome E middle part of habit, showing lateral culm F spike G utricles (above dorsal surface, below ventral surface) H nutlet (left dorsal surface, right ventral surface) I, K inflorescence.
The specific epithet ‘yangchunensis’ refers to the type locality of this new species in Yangchun County.
Flowering and fruiting all the year round.
The new species has been collected from the limestone regions of Kongdongyan Scenic Spot near Yangchun County, in Heshui and Chunwan townships. It is believed to be distributed in similar limestone hills near Yangchun County. It is currently known to grow on limestone landscapes at lower elevations of 60–80 m.
(paratypes). China. Guangdong (广东): Yangchun County (阳春), Chunwan Township (春湾镇), Gaocun Tourist Resort (高村旅游度假区), 14 October 2023, D. C. Meng s.n. (IBK, ZJFC, ZM); the same locality, 2 January 2024, D. C. Meng 2024010201 (ZJFC, ZM); Heshui Township (合水镇), Matangjiao Village (麻塘角村), 22.38104°N, 111.92091°E, elev. 76 m, 8 April 2024, X. F. Jin & Y. F. Lu 5192 (ZJFC, ZM); Kongdongyan Scenic Spot (崆峒岩景区), Banshanting (半山亭), 22.18571°N, 111.74601°E, elev. 67 m, 9 April 2024, X. F. Jin & Y. F. Lu 5198 (PE, ZJFC, ZM).
Least Concern (LC). The new species is a common sedge and grows on cliffs of the limestone regions around Yangchun County, Guangdong Province. Two known populations are in good status, but are strongly influenced by tourist activity, so that the species will need attention at related locations for conservation (
We are grateful to the curators and staff of the following herbaria, K, KYO, LE, P, PE, TI, WUK and ZJFC, for their kind help during the authors’ visit and to Mr. Philip E. Hyatt for improving the English.
The authors have declared that no competing interests exist.
No ethical statement was reported.
This work was supported by the National Natural Science Foundation of China (Grant No. 32070218) and the start-up scientific project of Zhejiang A&F University (Grant No. 2022LFR011).
Yi-Fei Lu and Xiao-Feng Jin conceived the study. Yi-Fei Lu, De-Chang Meng and Xiao-Feng Jin collected the samples. Yi-Fei Lu and De-Chang Meng conducted the measurements of morphological characters, data analysis and SEM observation. Yi-Fei Lu and Xiao-Feng Jin wrote the manuscript. All authors approved the final version of the manuscript.
Yi-Fei Lu https://orcid.org/0000-0001-6095-3821
De-Chang Meng https://orcid.org/0000-0002-1049-1232
Xiao-Feng Jin https://orcid.org/0000-0002-8195-6738
All of the data that support the findings of this study are available in the main text.
GenBank accession numbers of the species are listed below (species name: ETS, ITS, matK, rpl32trnL(UAG), trnL-F) and voucher information is provided for the newly-generated sequences:
C. aboriginum: MN760588, MN761648, GU172441, —, —; C. abscondita: MN759823, MN761824, GU172447, —, —; C. acaulis: MN760451, MN762256, MN763688, —, —; C. aestivalis: MN760562, MN761566, GU172459, —, —; C. aethiopica: MN759949, MN762349, MN763446, —, —; C. agastachys: MN761179, MN762597, MN763240, —, —; C. alajica: MN761331, MN762415, MN763374, —, —; C. alliiformis: MT920727, MT920759, MT920790,, MT920867; C. alterniflora: OR913315, OR668798, OR866295, OR913383, OR913257; C. angolensis: MN759931, EU288569, MN762971, —, —; C. angustata: MN760929, MN761518, GU172491, —, —; C. anhuiensis: OR913316, OR668799, —, OR913384, OR913258; C. antoniensis: MN760999, MN762074, MN763743, —, —; C. aperta: MN760847, MN761632, GU172500, —, —; C. asturica: MN761067, MN762464, MN763498, —, —; C. atrofusca: MN760042, MN761794, GU172555, —, —; C. baimaensis: MN760558, MN761417, MN763557, —, —; C. baohuashanica: OR913358, OR689467, OR866324, OR913429, OR913292; C. bigelowii: MN761315, MN762339, MN763487, —, —; C. blepharicarpa: MN759781, —, —, —, —; C. borii: MN761039, MN762187, MN763700, —, —; C. brainerdii: MN760630, MN761882, GU172612, —, —; C. breedlovei: MN760977, MN762091, MN763222, —, —; C. breviaristata: OR913318, OR668800, OR866296, OR913385, OR913259; C. breviculmis: OR913319, OR668801, OR866297, OR913386, OR913260; C. breviscapa: MN760015, MN762575, MN763013, —, —; C. bullata: MN761003, MN761622, GU172630, —, —; C. capillaris subsp. fuscidula: MN760542, MN762040, MN763516, —, —; C. cardiolepis: MN760171, MN762377, MN763696, —, —; C. caucasica: MN760600, MN762257, MN763745, —, —; C. chaofangii: MN759907, MN761627, —, —, —; C. cherokeensis: MN760098, MN761606, GU172677, —, —; C. chinensis: OR913320, OR668802, OR866298, —, OR913261; C. chlorocephala: OR913321, OR668803, OR866299, —, OR913262; C. chlorosaccus: MN759932, EU288577, MN763179, —, —; C. chordalis: MN761070, MN762558, MN763114, —, —; C. chuiana: OR913362, OR668841, OR866328, OR913412, OR913296; C. chuii: MW458996, MW459027, MW459094, OR913415, MW459058; C. chungii: OR913322, OR668804, OR866300, OR913387, OR913263; C. collinsii: MN760100, MN761432, GU172686, —, —; C. complanata: MN760661, MN761557, GU172701, —, —; C. concinnoides: MN760092, MN761930, GU172704, —, —; C. conica: OR913323, OR668805, OR866301, OR913388, OR913264; C. cretica: MN760085, MN762258, MN763412, —, —; C. cruenta: MN760446, MN762441, MN763817, —, —; C. cryptostachys: MN760888, MN762869, MN763020, —, —; C. cryptostachys 1: OR913324, OR668806, —, —, —; C. cryptostachys 3: PQ539318, PQ535885, PQ539321, PQ539325, PQ539329, Hainan, Mt. Wuzhishan, X.F. Jin 2992; C. dapanshanica: OR913325, OR668807, —, —, OR913265; C. daxinensis: OR913363, OR668842, OR866329, OR913413, OR913297; C. deflexa: MN760618, MN762102, GU172760, —, —; C. delicata: MN760541, MN762542, MN763772, —, —; C. demissa: MN760083, MN761875, GU173786, —, —; C. digitata: MN759970, MN762307, MN763754, —, —; C. doisutepensis: MN759938, MN762045, MN763478, —, —; C. durieui: MN760122, MN762351, MN763474, —, —; C. egena: OR913359, OR668838, OR866325,, OR913293; C. ericetorum: MN760026, MN762286, MN763731, —, —; C. esquiroliana: MN761064, MN762053, MN763585, —, —; C. fastigiata: MN759999, MN762056, MN763322, —, —; C. fissuricola: MN761373, MN762017, GU172869, —, —; C. flava: MN760063, JN634689, MN763787, —, —; C. fokienensis: MT920734, MT920766, MW459079, MT920838, MT920874; C. folliculata: MN760924, MN761465, GU172882, —, —; C. foraminata 1: —, OR668835, OR866322, —, —; C. foraminata 2: MN760492, MN761796, MN763018, —, —; C. frigida: MN759952, MN762466, MN763740, —, —; C. funhuangshanensis: OR913364, OR668843, OR866330, OR913414, OR913298; C. gifuensis: MN760643, MN761423, —, —, —; C. giraldiana: MN760554, MN761919, MN763526, —, —; C. glaucodea: MN759818, MN761439, FJ597209, —, —; C. globularis: MN760973, MN762535, MN763409, —, —; C. haematostoma var. alexeenkoana: MN761040, MN762444, MN763766, —, —; C. halleriana: MN760532, MN762338, MN763694, —, —; C. harlandii: MN760527, MN762606, MN763046, —, —; C. harrysmithii: MT920738, MT920770, MT920803, MT920842, MT920878; C. herbacoeli: MN761231, MN762157, MN763527, —, —; C. inanis: MN760504, MN762430, MN763678, —, —; C. ischnostachya: MT920741, MT920773, MT920806, MT920845, MT920881; C. ivanoviae: MN761038, MN762446, MN763803, —, —; C. japonica: MT920743, MT920774, MT920808, —, MT920883; C. kashmirensis: MN759944, MN762354, MN763301, —, —; C. lancisquamata: MN760906, MN762086, MN763314, —, —; C. lativena: MN760528, MN761490, GU173073, —, —; C. lemmonii: MN760021, MN761555, GU173090, —, —; C. lianchengensis: MN760555, MN761654, —, —, —; C. ligulata: MK481321, MK481341, MT920810, MT920846, MK481361; C. limosa: MN761060, MN761787, GU173120, —, —; C. liparocarpos: MN760648, MN762401, MN763805, —, —; C. lonchocarpa: MN760923, MN761429, GU173128, —, —; C. longicolla: OR913333, OR668813, —, OR913391, OR913269; C. longirostrata: MN761208, MN762075, MN763305, —, —; C. macrochaeta: MN760976, MN762098, GU173175, —, —; C. magellanica subsp. irrigua: MN760861, MN762190, MN763818, —, —; C. makinoensis: MN761145, MN762552, —, —, —; C. manciformis: MN760556, —, MN763629, —, —; C. maubertiana: MW458988, MW459019, MW459086,, MW459050; C. maximowiczii: OR913360, OR668839, OR866326, OR913409, OR913294; C. microchaeta: MN761263, MN761572, GU173216, —, —; C. mitrata var. aristata: OR913334, OR668814, OR866304, OR913392, OR913270; C. mollicula: MT920746, MT920777, MT920813, MT920848, MT920887; C. nodaeana: MN760553, MN762293, MN763800, —, —; C. oligocarya: MN760659, MN762404, MN763608, —, —; C. ornithopoda: MN759995, MN762308, MN763753, —, —; C. pedunculata: MN760639, MN761431, GU173371, —, —; C. pendula: MN761195, MN762602, MN763148, —, —; C. perraudieriana: MN760016, MN762134, MN763400, —, —; C. phacota: OR913361, OR668840, OR866327, OR913410, OR913295; C. picta: MN760546, MN761561, GU173398, —, —; C. pingleensis: OR913338, OR668817, OR866307, OR913395, OR913273; C. pisiformis: OR913339, OR668818, OR866308, OR913396, OR913274; C. polyschoena: OR913340, —, OR866309, OR913397, OR913275; C. prasina: MN760974, MN761582, GU173431, —, —; C. pseudotristachya: OR913337, —, —, —, —; C. pudica: MN759801, MN762546, —, —, —; C. pulchra: MN759942, —, MN763695, —, —; C. qingyangensis: MW458981, MW459012, MW459078, OR913411, MW459043; C. rainbowii: KC122388, KC122380, MN763804, —, —; C. reinii: MN760674, MN762213, —, —, —; C. richardsonii: MN759988, MN761635, GU173477, —, —; C. sartwelliana: MN760980, MN761649, GU173500, —, —; C. shangchengensis: MN759909, MN761578, MN763099, —, —; C. shortiana: DQ115273, DQ115272, —, —, —; C. sprengelii: MN760547, MN761413, GU173599, —, —; C. squarrosa: MN760967, MN761563, GU173603, —, —; C. stenocarpa: MN760110, MN762363, MN763676, —, —; C. strigosa: MN761116, MN762211, MN763217, —, —; C. stylosa: MN761010, MN761414, GU173641, —, —; C. tangulashanensis: MN760545, MN762246, MN763687, —, —; C. tomentosa: MN759974, MN762344, MN763732, —, —; C. transversa: MT920755, MT920786, MT920828, MT920863, MT920896; C. triquetra: MN759951, MN761924, GU173722, —, —; C. tristachya: OR913349, OR668827, OR866316, OR913401, OR913283; C. tristachya var. pocilliformis: OR913350, OR668828, —, OR913402, OR913284; C. tristis: MN760116, MN762438, MN763724, —, —; C. truncatigluma: OR913351, OR668829, OR866317, OR913403, OR913285; C. ulobasis: MN760557, —, MN763109, —, —; C. umbrosa: MN759791, MN762384, MN763798, —, —; C. umbrosa subsp. huetiana: MN760662, MN762420, MN763658, —, —; C. vestita: MN760966, MN761634, GU173772, —, —; C. yandangshanica: MN760559, MN761541, MN763047, —, —; C. yangchunensis 1: PQ539317, PQ535884, PQ539320, PQ539324, PQ539328, Guangdong, Yangchun, X.F. Jin & Y.F. Lu 5196; C. yangchunensis 2: PQ539315, PQ535882, —, PQ539322, PQ539326, Guangdong, Yangchun, D.C. Meng 2024010201; C. yangchunensis 3: PQ539316, PQ535883, PQ539319, PQ539323, PQ539327, Guangdong, Yangchun, D.C. Meng s.n.