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Research Article
Further investigation of Melocalamus (Poaceae, Bambusoideae) in China based on Skmer analysis and morphology
expand article infoYu-Jin Chen‡§, Mei Chen§‡, Meng-Yuan Zhou§, Zu-Chang Xu§‡|, Yu-Xiao Zhang, Jing-Xia Liu§, De-Zhu Li‡#§
‡ University of Chinese Academy of Sciences, Beijing, China
§ Chinese Academy of Sciences, Kunming, China
| Yunnan University, Kunming, China
¶ Southwest Forestry University, Yunnan, Malaysia
# Shandong Agricultural University, Shandong, China

Corresponding author: Jing-Xia Liu ( liujingxia@mail.kib.ac.cn )

Corresponding author: De-Zhu Li ( dzl@mail.kib.ac.cn )

Academic editor: Wei Lim Goh
© 2025 Yu-Jin Chen, Mei Chen, Meng-Yuan Zhou, Zu-Chang Xu, Yu-Xiao Zhang, Jing-Xia Liu, De-Zhu Li.
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: Chen Y-J, Chen M, Zhou M-Y, Xu Z-C, Zhang Y-X, Liu J-X, Li D-Z (2025) Further investigation of Melocalamus (Poaceae, Bambusoideae) in China based on Skmer analysis and morphology. PhytoKeys 259: 177-198. https://doi.org/10.3897/phytokeys.259.151683
Open Access

Abstract

Melocalamus is a genus of paleotropical woody bamboos distributed in Southeast Asia, characterised by its complex taxonomic history. Currently, the taxonomic status of several species within Melocalamus remains unresolved, primarily due to incompleteness of vegetative specimens for identification, coupled with scarcity of floral and fruit specimens and phylogenetic discordance. To address these issues, we developed a genome skimming dataset with multiple samples per species of Melocalamus through the Skmer approach. Genetic and morphological evidence supports the transfer of M. elevatissimus to Cephalostachyum, with a new combination, C. elevatissimum. Based on a comprehensive evaluation that integrates morphological characters, molecular data and geographic distribution, we propose treating M. utilis as a synonym of M. orenudus and provide the description of its inflorescence and an epitype of it for the first time. Our results further indicate that M. ningmingensis is a synonym of Neomicrocalamus prainii. We also described a new species, M. guangxiensis from Ningming, Guangxi, based on morphological and molecular evidence. Our results demonstrate both the efficiency and reliability of the Skmer approach in species discrimination while emphasising the importance of integrating morphological characters with genomic data for accurate species classification in Melocalamus.

Key words:

Cephalostachyum, epitype, genome skimming, Neomicrocalamus, new combination, new species, new synonyms

Introduction

Melocalamus Benth. is a genus of the subtribe Bambusinae in continental Southeast Asia, which belongs to the paleotropical woody bamboos clade (PWB) (Poaceae, Bambusoideae) (Zhou et al. 2017; Liu et al. 2024a). The genus was established by Bentham with Melocalamus compactiflorus (Kurz) Benth (based on Pseudostachyum compactiflorum Kurz) as its type (Bentham 1883). Melocalamus has long been treated as a monospecific genus (Clayton and Renvoize 1986) because of limited fieldwork and scarcity of herbarium specimens. However, recent studies indicate that it comprises about 14 species (Soreng et al. 2022) with additional new combinations and newly-described species (Liu et al. 2023; Chen et al. 2025). The identification of bamboo species mainly relies on vegetative characters; thus, in the absence of flowering specimens, distinguishing Melocalamus from morphologically similar genera such as Dinochloa Buse (Liu et al. 2023) and Maclurochloa K.M. Wong (Wong 1993) becomes particularly challenging, because these genera are also climbing bamboos in Southeast Asia with one main branch as thick as the main culm. With the advancement of molecular phylogenetics, phylogenomics (Guo et al. 2023) and increased field investigations, it is now feasible to accurately identify new species and taxonomic combinations within Melocalamus (Zhou et al. 2017; Qin et al. 2019; Liu et al. 2023), even leading to the recognition of a new genus within the PWB clade (Haevermans et al. 2020).

Species of Melocalamus are distributed in humid and warm environments across tropical and subtropical regions of China and mainland Southeast Asia, with documented occurrences in south China (Yunnan, Hainan and Guangxi), Myanmar, Thailand, Laos and Vietnam. According to Flora Reipublicae Popularis Sincae (Keng and Wang 1996) and Iconographia Bambusoidearum Sinicarum (Yi et al. 2008), the diagnostic morphological characters of Melocalamus can be summarised as follows: climbing habit; multiple branches with one dominant branch as thick as main culm; prominent nodes, with a ring of powder/tomenta above and below the sheath scars; pseudospikelets bearing 2–3 florets with a sterile terminal floret that forms head-like inflorescences.

Although classified within the distantly-related PWB subtribe Melocanninae (Zhou et al. 2022), Cephalostachyum Munro exhibits vegetative convergence with Melocalamus particularly amongst climbing species such as Cephalostachyum scandens Bor and C. mannii (Gamble) Stapleton & D.Z. Li. The dominant branch of these two species is well-developed and as thick as the main culm, allowing it to substitute for the main culm for climbing. In addition, both genera have overlapping distributions in China. However, Cephalostachyum can be distinguished from Melocalamus by its reproductive traits such as the prominent bracts below the pseudospikelets, each pseudospikelet containing only one floret and nut-like caryopsis with a persistent style base, supplemented by vegetative differences including glabrous nodes and generally thinner culm walls.

The taxonomic validity of several Melocalamus species remains unresolved. Melocalamus elevatissimus Hsueh & T.P. Yi, published in 1983 (Yi 1983), is the only species of Melocalamus reported in Xizang. It exhibits morphological affinities to Cephalostachyum; however, there has been limited collection and rare research since its publication. Furthermore, Melocalamus gracilis W.T. Lin (type specimen: Feipeng Chen 4726, deposited at CANT) was described from vegetative material collected in Ningming, Guangxi (Lin 1993). As it is a later homonym of M. gracilis R.B. Majumdar (Karthikeyan et al. 1989), which is illegitimate according to the Code (Turland et al. 2025), it was renamed by Ohrnberger (1997) as M. ningmingensis. Liu et al. (2023) temporarily treated it as incertae sedis. Based on careful examination of the type specimen, we find that it shares significant similarities to Neomicrocalamus prainii. Additionally, the vegetative traits of Melocalamus orenudus and M. utilis are extremely similar. In short, the taxonomic status of these species needs further investigation.

To address above questions, we conducted extensive investigation into the species of Melocalamus in China following our previous work (Liu et al. 2023; Chen et al. 2025). We collected multiple individuals per species and detailed morphological comparisons to verify the identities within Melocalamus species. A genome skimming dataset was developed using Skmer analysis to further support morphological identifications. The integration of morphological and genetic analyses enabled us to revise the taxonomic position of both M. elevatissimus and M. ningmingensis and to assess the relationships between M. orenudus and M. utilis. In addition, we provide a detailed description of inflorescence for M. orenudus and describe as well as illustrate a new species of Melocalamus from Guangxi, China.

Material and methods

Morphology observation

To determine the taxonomic status of Melocalamus elevatissimus, we reviewed relevant literature before carrying out fieldwork in the type locality and compared specimens in the Herbarium of Kunming Institute of Botany, Chinese Academy of Sciences (KUN). We measured a batch of diagnostic characters including branch complement, culm leaves, internodes, nodes and foliage leaves to compare it with two related species (M. compactiflorus and Cephalostachyum latifolium) with living materials, herbarium specimens and images whenever available.

Our previous work found that an individual of Melocalamus utilis was clustered with M. orenudus (Liu et al. 2023). To check the taxonomic status, we collected additional living materials and specimens of these two species in Hainan and observed relevant specimens from KUN and Herbarium of Sun Yat-sen University (SYS).

We also carried out a field survey of Melocalamus ningmingensis in the type locality, Ningming, Guangxi in 2023 and carefully examined the type specimen (Feipeng Chen 4726) in the Herbarium of South China Agricultural University (CANT) to determine the status of the taxon incertae sedis in Liu et al. (2023).

Molecular sampling and analyses

Taxon sampling

A total of 58 individuals were sampled, including 42 individuals of Melocalamus (12 species and one variety collected in China, Myanmar and Thailand). To solve the existing taxonomic problems within Melocalamus, 11 individuals of nine taxa from subtribe Bambusinae were chosen as closely-related species and five individuals of four species from subtribe Melocanninae as outgroups following Zhou et al. (2017) and Liu et al. (2024a). Amongst them, genome sequencing data of Dendrocalamus latiflorus Munro, D. sinicus L.C. Chia & J.L. Sun and Melocanna baccifera (Roxb.) Kurz were downloaded from BambooBase (https://bamboo.genobank.org/) (Liu et al. 2024b) and GenBank (https://www.ncbi.nlm.nih.gov/genbank/) (ID: SRR11805848, SRR25459136 and SRR25498978). All examined and voucher specimens are deposited in the KUN Herbarium unless specified. Sample information is detailed in Suppl. material 1: table S1.

DNA sequencing and data cleaning

Silica-gel dried leaves or specimens were used for DNA extraction, library preparation and sequencing. Skmer analysis can achieve satisfactory results using only 1× sequencing depth (Sarmashghi et al. 2019). Given the genome size of Melocalamus species is below 2 Gb, we extracted a volume of 2 GB dataset from the sequencing data using Seqkit v.2.3.0 (Shen et al. 2016), with single-end sequencing data comprising 1 GB (approximately 8,000,000 reads). Fastp 0.21.0 (Chen et al. 2018) was used for quality control of raw reads with the default parameters. The sequencing quality of samples are shown in Suppl. material 1: table S2.

Dataset construction and phylogenetic analyses

We performed independent Skmer (Sarmashghi et al. 2019) analyses by utilising two distinct datasets: one included all clean reads, while the other excluded plastid and mitochondrial reads aiming to evaluate whether the inclusion of organellar genomes would influence the final topological structure. Before initiating analysis, Bowtie2 v.2.3.4.1 (Langdon 2015) was utilised to establish plastid and mitochondrial reference for the purpose of removing plastid and mitochondrial sequences from the sequencing data, plastome reference from Melocalamus arrectus T.P. Yi (MK679766.1) and mitochondrial genome sequences of Ferrocalamus rimosivaginus T.H. Wen (Ma et al. 2012). Then BBMerge (Bushnell et al. 2017) was used to merge overlapping read pairs with default parameter settings. We used “skmer reference” and “skmer subsample” commands to obtain a main estimate distance matrix and 100 sub-replicates. By utilising the “skmer correct” command, we performed correction of 100 subsampled distance matrices ultimately obtaining correct genomic estimates. Then, these standard square distance matrices were converted to PHYLIP format. FastME 2.1.6.4 (Lefort et al. 2015) was used to infer phylogenies from the reformatted distance matrices. We used RAxML v.8.2.12 (Stamatakis 2014) to construct an extended majority rule consensus tree with the model “GTRCAT”. The PHYLIP format subsampled distance matrices for the analysis reported in this paper were deposited in the Science Data Bank at https://doi.org/10.57760/sciencedb.26005.

Results

Morphological comparison

Morphologically, Melocalamus elevatissimus is similar to species of Melocalamus in terms of vegetative characters, such as climbing habits, branches several to many, one dominant branch as thick as main culm, with white powder under nodes and it somewhat resembles M. compactiflorus. However, M. elevatissimus can be distinguished from M. compactiflorus by the following suite of diagnostic characters: (1) culm leaves lack auricles, with apices protruding into thin projections (1–2 cm on each side); (2) culm leaf blades are lanceolate, characterised by a base that does not contract into a rounded shape; (3) foliage leaf sheaths possess elongated oral setae extending to the mid-region, without auricles. However, M. elevatissimus is more similar to Cephalostachyum in glabrous internodes (without siliceous), smooth nodes, without white powder/tomenta above the nodes and culm leaf sheaths with obvious transverse veins. After comparing it with all the species of Cephalostachyum, we found that M. elevatissimus is mostly similar to Cephalostachyum latifolium, mainly reflected in thin culm leaf sheaths with obvious longitudinal ribs abaxially and with obvious oral setae. However, M. elevatissimus usually has one main branch as thick as culm; foliage leaf sheaths with fimbriate grey-white long oral setae, margins with fringed cilia; while C. latifolium usually has many subequal branches, sometimes with 1–2 thicker ones, without main branches; foliage leaf sheaths with caducous white straight oral setae, margins without cilia. We presented/summarised the morphological character differences of M. compactiflorus, M. elevatissimus and C. latifolium in Fig. 1 and Table 1, respectively.

Figure 1. 

Comparison of morphological characters amongst Cephalostachyum latifolium, Melocalamus elevatissimus and Melocalamus compactiflorus.

Table 1.
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Morphological comparison amongst Melocalamus compactiflorus, Melocalamus elevatissimus and Cephalostachyum latifolium.

Characters/Species Melocalamus compactiflorus Melocalamus elevatissimus Cephalostachyum latifolium
Culm leaves Sheaths Persistent; thickly leathery; with white powder abaxially; without obvious longitudinal veins and transverse veins Persistent; leathery; with light-yellow spiny hairs abaxially; with obvious longitudinal veins and transverse veins Deciduous; leathery, with sides papery; densely brown hairs abaxially; with obvious longitudinal veins and transverse veins
Apex Truncate, flat With thin projections 1–2 cm on each side Round, projecting upward on both sides
Ligules Entire, narrow Depressed, ca. 0.1 cm Narrow
Auricles Crescent-shaped, reflexed Absent Inconspicuous
Oral setae Absent Caducous grey-white long hairs Caducous fimbriate long hairs
Blades Circular at the base, reflexed Lanceolate, reflexed or erect Lanceolate, reflexed or erect
Foliage leaves Apex Flat Protruding Protruding, circular
Ligules Entire, narrow Depressed, ca. 0.1 cm Truncate, short
Auricles Crescent-shaped, reflexed Absent Inconspicuous
Oral setae Absent With curly fimbriate grey-white long oral setae Caducous, with white straight oral setae
Blades (length × width) 15–25 cm × 3–3.5 cm, lanceolate 17–28 cm × 3–9 cm, oblong-lanceolate 25–30 cm × 8–10 cm, ovate-elliptic
Culms Walls 1–2.5 cm in diam.; wall thick to solid 1.5–3 cm in diam.; wall 0.3–0.4 cm 3.5 cm in diam.; wall 0.2–0.3 cm
Internodes Rough, with siliceous Glabrous Glabrous
Nodes Prominent, with tomenta Smooth, glabrous Smooth, glabrous
Branches Many, with one dominant branch Many, with one dominant branch Many, without dominant branch

We summarised the distinctions outlined in the literature regarding Melocalamus utilis and M. orenudus. Both the morphological characteristics described in original literature (McClure 1940) and our previous work (Liu et al. 2023) concur that the primary morphological differences between the two species are summarised as follows: 1) M. utilis has narrow culm leaf auricles, while culm leaf auricles are absent in M. orenudus; 2) The culm leaf sheaths of M. utilis have white spiny hairs, while the culm leaf sheaths of M. orenudus have appressed white pubescent; 3) The foliage leaf sheaths of M. utilis are slightly striped and glabrous, while the foliage leaf sheaths of M. orenudus have pubescent and white powder. Through investigation in Lingshui and Baoting, Hainan, the type localities and re-examination of specimens, we found that the two species exhibit high similarity: 1) The culm leaf auricles of M. utilis are also frequently absent; 2) Overall, the culm leaf sheaths of both species are powdery and covered with white pubescence; 3) The foliage leaf sheaths of both species are slightly striped and glabrous in specimens and the tender foliage leaf sheaths are covered with easily deciduous short hairs and white powder in living materials.

As for Melocalamus ningmingensis, due to the type specimens providing limited information, especially the incomplete culm leaf sheaths, we could neither find the blade information of culm leaf sheaths in the protologue of Lin (1993) nor from the type specimen (Feipeng Chen 4726). In addition, we could not observe the branch sheaths described in the part 6 of fig. 1 from the type specimen either (Lin 1993). It is difficult to undertake further comparison in morphology. Through detailed examination of the original descriptions and the meticulous observation of the type specimen, we have determined that only the common climbing habit and the branches exhibit similarities to Melocalamus and neither culm diameter (only 5–8 mm) nor glabrous nodes/culms match the characteristics of Melocalamus. Instead, these features are more consistent with those of Neomicrocalamus. In addition, according to the type specimens, there is no ring of powder and/or tomenta above and below the sheath scars, internodes smooth, culm leaf sheaths with brown spotted abaxially. These characters are matched well with Neomicrocalamus prainii (Gamble) Keng f. (Keng 1983), rather than N. andropogonifolius (Griff.) Stapleton (Stapleton 1994) or N. dongvanensis T.Q. Nguyen (Nguyen 1991). Vegetatively, N. andropogonifolius has hollow culms and glabrous culm leaf sheaths without bristle, while Feipeng Chen 4726 has solid culms and culm leaf sheaths with brown spots and small bristles. N. dongvanensis has upright culms, while Feipeng Chen 4726 has drooping culms.

During our field survey in the type locality of Melocalamus ningmingensis within the Longrui Nature Reserve, Ningming, Guangxi, we collected a potentially new species named Melocalamus guangxiensis D.Z. Li & J.X. Liu (collection number: Xuzc2023109, PX001) which possess key diagnostic features of Melocalamus, including the prominent nodes, with a ring of tomenta above and below the sheath scars, many branches with one dominant branch replacing the main culm. The characters of foliage leaf auricles with radiate oral setae which are similar to Melocalamus puberulus (McClure) D.Z. Li & J.X. Liu (Liu et al. 2023), M. cordatus (T.H. Nguyen Wen & Q.H. Dai) D.Z. Li & M.Y. Zhou (Zhou et al. 2017), M. pacoensis H.N. Nguyen & V.T. Tran (Nguyen and Tran 2010), M. truongsonensis H.N. Nguyen & V.T. Tran (Nguyen and Tran 2010) and M. compactiflorus var. fimbriatus (Hsueh & C.M. Hui) D.Z. Li & Z.H. Guo. In addition, the characters of culm leaf ligules with fringed long setae at the apex are mostly similar to M. pacoensis, M. truongsonensis, M. puberulus and M. compactiflorus var. fimbriatus, but could be easily identified with the different culm leaf blades: only the culm leaf blades of M. guangxiensis are not constricted to round shape or narrow at the base part. The unique character of M. guangxiensis is the base of the outer margin of culm leaf sheaths with a membranous projection, ca. 1–2 cm. Apart from the presence of an inconspicuous membranous projection at the base of the outer culm sheath margin in M. yunnanensis, this feature has not been observed in any other Melocalamus species. The comparation of culm leaves and foliage leaves within M. guangxiensis and the above six taxa is presented in Fig. 2 and Table 2.

Figure 2. 

Diagnostic characters of foliage leaves and culm leaves amongst M. guangxiensis and closely-related species (The bases of culm sheaths are missing in M. pacoensis and M. truongsonensis because there are no relevant pictures available (Nguyen and Tran 2010)).

Table 2.
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A comparison of culm leaves and foliage leaves amongst Melocalamus guangxiensis and closely-related species.

Characters /Species M. guangxiensis M. pacoensis M. truongsonensis M. puberulus M. compactiflorus var. fimbriatus M. cordatus M. yunnanensis
Culms (cm) Culms diameter 1.0–2.0 1.8–2.3 2.0–3.0 2.0–3.5 2.0–4.0 2 (1–)2.0–3.0
Culm walls thickness 0.4–0.5 0.8 solid 0.4 0.8–1.3 0.5 0.5–0.7
Internodes length 50–80 80–85 58–60 30–50 25–35(–45) 40–60 40–60
Culm leaf sheaths (cm) Base Base of outer margin with a membranous projection, ca. 1–2 cm Base without a projection Base without a projection Base without a projection Base without a projection Base without a projection Base of outer margin with an inconspicuous projection
Outer surface With white powder and brown hairs With smooth, fugacious, black hairs With dense, soft, appressed, black hairs With white powder and black hairs With caducous white hairs With yellow pubescent With brown cilia
Auricles Erect or recurved, wavy, narrow, with several fimbriate long oral setae 4–4.5 × 0.5–0.6 cm, rounded, serrate, with 2 cm long stiff hairs 0.5–0.8 × 0.6–0.7 cm, stiff, thick, deflexed, with two lines of 2.2 cm long hairs. Conspicuous, reflexed, wrinkled, with radiated oral setae, 1.5–2.5 cm long Inconspicuous Ovate, with fimbriate oral setae or inconspicuous Absent
Ligules 0.2–0.3 cm, uniformly serrated, apex with fimbriate hairs, 1–1.5 cm long Rounded, with sparse, 1.2 cm long hairs 0.2 cm, with fugacious hairs, become serrate after shedding 0.15–0.4 cm, apex wide arched, fimbriate 0.2–0.5 cm, prominent, with 0.8–1 cm fimbriate hairs 0.1 cm, edge with cilia 0.1 –0.3 cm, apex truncate or prominent
Blades 6–8 × 0.7–0.9 cm, lanceolate 13–19 × 4.5–6.5 cm, triangular, round at the base 4–7 × 0.5–0.8 cm, round/cordate at the base 2–2.5 × 16–18 cm, lanceolate, round/cordate at the base 2–18 × 11.8–2.5 cm, ovate-lanceolate, round/cordate at the base 25–32 × 9–10 cm, ovate-lanceolate, with equal width of sheath apex (4–)7–10.5 × 0.8–1.0 (–1.3) cm, ovate-lanceolate
Foliage leaf sheaths (cm) Auricles Sickle-shaped, with radiated oral setae 0.2–0.8 cm, undulated, with sparse, stiff oral setae 2.5 cm long 0.1–0.3 cm, curved outwards, with dense, stiff, oral setae 1.5 cm long Conspicuous, oral setae radiated, 1–1.5 cm long Absent Sickle-shaped, oral setae, 1.3 cm long Absent
Ligules 0.1–0.2 cm, apex truncate or with inconspicuous serrated, with fimbriate long hairs, 1 cm long 0.2 cm, with sparse stiff hairs Short 0.1–0.2 cm, fimbriate, apex truncate 0.1 cm, apex serrated 0.1 cm Inconspicuous
Distribution Guangxi, China Vietnam Vietnam Yunnan, China Yunnan, China Hainan, China Yunnan, China

Over-reliance on some diagnostic characters while overlooking other morphological characters could result in misclassifications. In the case of ambiguous Melocalamus species, the identification of M. elevatissimus and M. ningmingensis were mainly based on the presence of a branch as thick as the culm and their climbing habit, which led to the incorrect identification as Melocalamus. However, our molecular and morphological comparison results all support the species that should belong to Cephalostachyum and Neomicrocalamus, respectively, because these three genera all have main branches and are all climbing bamboo species. However, the most conspicuous distinctions amongst these three genera are based on the character on culms and culm leaves. We have summarised these key diagnostic characters in Table 3.

Table 3.
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A comparison of key morphological characters amongst Cephalostachyum, Melocalamus and Neomicrocalamus.

Characters/Genus Cephalostachyum Melocalamus Neomicrocalamus
Culm Walls Hollow Solid or sub-solid or hollow Solid or sub-solid
Internodes Glabrous Rough, with siliceous Glabrous
Nodes Smooth, glabrous Prominent, with tomenta Smooth, glabrous
Culm leaves Auricles and oral setae Prominent Prominent or with highly elevated shoulders or absent Absent
Blades Lanceolate Lanceolate, round/cordate at the base Conical

Skmer tree of Melocalamus species with uncertain taxonomic status

The total length of sequences ranges from 1,126,690 to 2,315,977 kb. After removing plastid and mitochondrial reads, the sequence length ranges from 1,095,340 to 2,254,224 kb.

The topological structures constructed from the two datasets are completely identical, which divide all individuals into two main clades: Melocanninae and Bambusinae (Fig. 3 and Suppl. material 2). Four individuals of Melocalamus elevatissimus form a monophyletic clade, which is closely related to Cephalostachyum latifolium, indicating that this species is a member of Cephalostachyum (purple marked in Fig. 3), based on the Skmer tree. The type specimen of Melocalamus ningmingensis (Feipeng Chen 4726) (blue marked in Fig. 3) is clustered with Neomicrocalamus prainii, which is consistent with its morphological characteristics. The other 37 individuals of Melocalamus form a well-supported monophyletic clade. Putative conspecific individuals are grouped in their respective clades, except for the seven individuals of M. utilis and three individuals of M. orenudus (yellow marked in Fig. 3), which together comprise a highly-supported subclade. The interspecific boundaries are not clear for the two species, rendering our proposal to combine M. utilis into M. orenudus. The new species M. guangxiensis is closely related to M. putaoensis D.Z. Li & J.X. Liu (Chen et al. 2025) but can be easily distinguished by the differences in morphological characteristics: the culm sheaths of M. guangxiensis possess a membranous projection, while those of M. putaoensis lack this structure; M. guangxiensis exhibits wavy auricles with several long fimbriate oral setae, whereas M. putaoensis lacks both auricles and oral setae.

Figure 3. 

The topology of the sampled Melocalamus with its related taxa, based on the Skmer analysis with all reads. Coloured boxes indicate the doubtful species and the species names in parentheses indicate the corresponding names before being revised in this study. Types of generic names are in bold.

Discussion

Skmer approach is efficient and reliable in species identification of Melocalamus

Based on the distance matrices, we reconstructed a stable Skmer tree of Melocalamus with high support values. The monophyly of Melocalamus and all the 10 revised taxa with multiple samples (except M. compactiflorus with only one individual) has been confirmed, consistent with previous results obtained from nuclear genes, including SNPs derived from dd-RAD data (Liu et al. 2020; 2023; 2024a) and syntenic nuclear genes (Chen et al. 2025). However, the phylogenetic tree constructed from plastid loci did not to support the monophyly of Melocalamus and exhibited low stability in topological structure (Zhou et al. 2017; Liu et al. 2020).

Zhang et al. (2023) compared species identification rates amongst different barcodes, based on a dataset of 50 species of Cymbidium Sw. (Orchidaceae). Through Maximum Likelihood (ML) tree analysis, the identification rate, based on the plastome, increased to 68%, compared to 58% for the standard barcodes (rbcL + matK + trnH-psbA) and the Skmer approach enhanced the identification rate to 72%. In another study focusing on 13 taxa of Schima Reinw. ex Blume (Theaceae) (Duan et al. 2024), it was found that the standard barcoding markers (rbcL + matK + trnH-psbA) lacked sufficient resolution, while the plastome raised the identification rate to 27.27% and the Skmer approach achieved an identification rate of 60%. Notably, the topological structure constructed using the Skmer approach correlated well with both morphological characteristics and geographical distribution within Schima. The two studies suggest that, based on a large amount of nuclear data, the Skmer approach enhances the accuracy and sensitivity in species identification when compared to the standard barcoding markers and plastome data.

In addition, the Skmer method eliminates the plastome assembly and sequence alignment steps by enabling intergenomic distances calculations using low-coverage sequencing data while demanding minimal computational resources. The confirmation of monophyly in Melocalamus species along with improved resolution of interspecific relationships in this study underscores that the Skmer approach is an efficient and reliable strategy for species identification within Melocalamus.

Revision of species with uncertain status in Melocalamus

Based on the stable topology of Melocalamus, reconstructed using the Skmer approach, Melocalamus elevatissimus and Cephalostachyum latifolium form a sister group in a separate clade, while all other samples form another clade. However, Melocalamus ningmingensis and three individuals of Neomicrocalamus prainii exhibit the closest relationship, rather than with other species of Melocalamus, which correspond well with our morphological comparison. Within the Melocalamus clade, individuals of M. orenudus and M. utilis mix with one another, but together cluster into a highly-supported subclade. The potentially new species, Melocalamus guangxiensis is not related to the type specimen of M. ningmingensis and can be distinguished from other species of Melocalamus, confirming its identity suggested by morphological analysis. Therefore, we treat these doubtful species as follows.

Taxonomic treatment

Cephalostachyum elevatissimum (Hsueh & T.P. Yi) D.Z. Li, Y.X. Zhang & Y.J. Chen, comb. nov.

urn:lsid:ipni.org:names:77364889-1
Fig. 4 Local names. Sang Rong, Ping Er. Chinese name. “西藏空竹” (xī zàng kōng zhú).

≡ Melocalamus elevatissimus Hsueh & T.P. Yi, J. Bamboo Res. 2(1): 28, 1983.

Type.

China • Xizang: Linzhi City, Motuo County, Beibeng Town, Deergong, alt. 940–2000 m, 15 Aug 1977, T.P. Yi 77183 (holotype, SIFS!, without barcode).

Description.

Perennial. Rhizomes pachymorph, short-necked. Culms apically scrambling, ca. 17 m long, 1.4–3 cm in diam.; internodes terete, glabrous, 40–90 (–120) cm long, wall 0.2–0.4 cm thick; nodes flat, glabrous; white powdery below the nodes; sheath scars prominent. Primary branch buds solitary, ovate-elliptical, compressed. Branches many, subequal or occasionally with a dominant branch replacing main culm. Culm leaves tardily deciduous, 24–38 cm × 8–12 cm, 2/5 to 1/2 as long as the internodes; sheaths leathery, long-triangle, with appressed light-yellow spiny hairs abaxially, margins glabrous, apex U-shaped and projecting upward sides, papery, with fimbriate grey-white long oral setae; auricles absent; ligules truncate, short, ca. 1 mm in length, margin extremely shortly ciliolate or subglabrous; blades linear-lanceolate, erect or reflexed, 5–30 cm × 1–1.9 cm. Foliage leaves 6–9 per ultimate branch; sheaths 8–16 cm long, abaxially glabrous, apex with fimbriate grey-white long oral setae, 4–11 mm long; margins with fringed cilia, 6–15 mm long; auricles absent; inner ligules truncate, dark-purple, ca. 1 mm in length; outer ligules present, truncated; blades oblong-lanceolate, 17–28 cm × 3–9 cm, with white pubescence abaxially, margins coarse, secondary veins 5–12 paired. Inflorescence and caryopsis unknown.

Figure 4. 

Cephalostachyum elevatissimum (Hsueh & T.P. Yi) D.Z. Li, Y.X. Zhang & Y.J. Chen. A. Habitat; B, H. Branch complement; C. A complete internode with culm leaf sheath; D. Culm leaf sheath apex; E. Node and culm bud; F. Transection of main culm; G. Foliage leaf sheath.

Phenology.

New shoots May to August.

Additional specimens examined.

China • Xizang: Linzhi City, Motuo County, alt. 1995 m, 15 Jul 2021, Z.Y. Xiahou XHZY2021003; • ibid., 30°1'7.097"N, 94°59'44.77"E, alt. 2061 m, 13 Jun 2023, P.F. Ma et al. BPG II 23141; • ibid., 29°38'48.75"N, 95°29'4.70"E, alt. 1903 m, 14 Jun 2023, P.F. Ma et al. BPG II 23148; • ibid., 29°14'37.071"N, 95°11'16.95"E, alt. 1302 m, 15 Jun 2023, P.F. Ma et al. BPG II 23159; • ibid., 29°10'50.10"N, 95°8'36.56"E, alt. 1736 m, 15 Jun 2023, P.F. Ma et al. BPG II 23163; • Xigaze City, Yadong County, Xiayadong, alt. 1625 m, 16 Jul 2021, J.D. Ya et al. 21CS20510; • ibid., 27°14'4.89"N, 89°1'2.89"E, alt. 1684 m, 6 Jun 2023, P.F. Ma et al., BPG II 23019.

Note.

Melocalamus elevatissimus was the first species of Melocalamus published in China (Yi 1983), which has a narrow distribution area in southern Xizang, confined to Motuo and Yadong, as well as the Yarlung Zangbo Grand Canyon National Nature Reserve, Xizang (Wu et al. 2022). Cephalostachyum elevatissimum does not overlap with the distribution area of other Melocalamus species (distributed in the Yunnan, Guangxi and Hainan Provinces of China, as well as Thailand, Myanmar, Vietnam and other Southeast Asian countries), but shares a common range with Cephalostachyum (Fig. 5). In addition, Melocalamus are predominantly found at altitudes ranging from 200 to 1300 m, while C. elevatissimum in Xizang mainly inhabits areas in higher altitudes (mainly 1300 to 2060 m).

Figure 5. 

Geographical distribution variations of Cephalostachyum elevatissimum (blue dots), other species of Cephalostachyum (red dots) and species of Melocalamus (black dots).

Melocalamus orenudus (McClure) D.Z. Li & J.X. Liu.

Fig. 6 Chinese name. “无耳梨籐竹” (wú ěr lí téng zhú).

Melocalamus orenudus (McClure) D.Z. Li & J.X. Liu, Plant Divers. 45: 137, 2023.

≡ Dinochloa orenuda McClure, Lingnan Univ. Sci. Bull. 9: 18, 1940.

= Melocalamus utilis (McClure) D.Z. Li & J.X. Liu, Plant Divers. 45: 138, 2023, syn. nov. ≡ Dinochloa utilis McClure Lingnan Univ. Sci. Bull. 9: 20, 1940.

Type.

China • Hainan: Lingshui County, Chim Shan, Fan Maan Ts’uen and vicinity, 3–20 May 1932, H. Fung 20230 (holotype, US!, Catalogue No.: 2802829, Barcode: 00065462); • Ledong County, Jianfengling National Nature Reserve, 18°42'21.03"N, 108°52'6.04"E, alt. 826 m, 02 Nov 2023, M.Y. Zhou, J.X. Liu & Z.C. Xu BPG II 23238 (epitype designated here, KUN!).

China • Hainan, Ling Shui District, Chim Shan, Fan Maan Ts’uen and vicinity, 4–20 May 1932, McClure 20136 (holotype, US!, Catalogue No.: 2802831, Barcode: 00065464; isotype, US!, Catalogue No.: 2767635, Barcode: 00036336; No.: 2767636, Barcode: 00036337).

Description.

Perennial. Rhizomes pachymorph, short-necked. Culms slender, 10–20 m long, 2–5 cm in diam., wall ca. 0.5 cm thick; internodes initially with white pubescence, 30–60 cm long; nodes prominent; sheath scars with a ring of white-yellow tomenta above and below. Branches several to many, with one dominant branch sometimes replacing main culm. Culm leaves shorter than internode; sheaths leathery, with white spiny hairs and powder abaxially, apex slightly concave; auricles narrow, extending upwards or absent; oral setae absent; ligules 1–2 mm in length, denticulate; blades lanceolate, round/cordate at the base, recurved. Foliage leaves 7–15 per ultimate branch; sheaths glabrous, tender sheaths are covered with easily deciduous short pubescence and white powder; auricles narrow or absent; ligules entire, ca. 1 mm in length; blades length 13–21 cm × width 3–4.5 cm, with white pubescence abaxially; margins coarse.

Flowering branches lateral or terminal; internodes 1–15 cm long, with white pubescence. Pseudospikelets lanceolate, top and edge purple, bottom yellow-green, 1–1.2 cm long, several to many clustered on nodes, glomerate, mixed with some small sterile and hay bracts; 3 florets in each psedospikelet with the top one sterile, fertile ones sessile. Glumes 2–3, ovate, 2–5 mm long, 2–3 mm wide, margins smooth. Fertile lemma lanceolate, thick membranous, glabrous, yellow, with top and edge purple, ca. 6–12 mm long. Palea nearly equal as lemma in size, lanceolate, membranous, navicular, 2 keels, margins with white cilia, yellow, with top and edge purple. Lodicules 3, 2 equal-sized, ca. length 2.7 mm × width 1.3 mm, one smaller, ca. length 2 mm × width 1 mm, bottom transparent with top light-purple, margins with long cilia. Stamen 6, distinct, anthers purple-red, sometimes yellow, 5–6 mm long, filament white. Ovary ovate-lanceolate, yellow-green; style 1, stigmas 3, plumose, white. Caryopsis unknown.

Figure 6. 

Melocalamus orenudus (McClure) D.Z. Li & J.X. Liu. A. New shoot, showing sheath auricle and ligule; B. Foliage leaves, showing foliage leaf sheaths; C. Habitat; D. Culms with culm leaf sheaths, branch complement and node with bud; E, F, H. Inflorescence and pseudospikelets; G. Stamens (s), lemma (le), palea (p), ovary (o), three lodicules (lo) and two glumes (g).

Phenology.

New shoots May to July.

Additional specimen examined.

China • Hainan: Baoting County, Ganzhaling Nature Reserve, 22 Aug 2018, J.X. Liu & Z.C. Xu Liujx18063; • Baoting County, Nangai 2 Road, 18°32'47.28"N, 109°31'34.43"E, alt. 354 m, 01 Nov 2023, M.Y. Zhou, J.X. Liu & Z.C. Xu BPG II 23232; • ibid., 18°33'5.01"N, 109°33'48.76"E, alt. 238 m, 01 Nov 2023, M.Y. Zhou, J.X. Liu & Z.C. Xu BPG II 23234; • Changjiang County, Bawangling National Nature Reserve, 19°7'13.04"N, 109°6'37.25"E, alt. 388 m, 03 Nov 2023, M.Y. Zhou, J.X. Liu & Z.C. Xu BPG II 23244; • Lai area, Hung Mo Shan and vicinity, 16 May 1929, Tsang, Tang & Fung, 17725 (SYS!); • Lingshui County, Chim Shan, Fan Maan Ts’uen and vicinity, 4–20 May 1932, F.A. McClure 20087 (SYS!); • Lingshui County, Diaoluo Mountain National Nature Reserve, 18°41'21.12"N, 109°52'43.68"E, alt. 612 m, 10 Jul 2017, M.Y. Zhou et al. zmy034; • ibid., 24 Aug 2018, J.X. Liu & Z.C. Xu Liujx18076; • ibid., 18°42'2.48"N, 109°50'10.38"E, alt. 511 m, 31 Oct 2023, M.Y. Zhou, J.X. Liu & Z.C. Xu BPG II 23221; • ibid., 18°40'8.33"N, 109°54'10.75"E, alt. 236 m, 31 Oct 2023, M.Y. Zhou, J.X. Liu & Z.C. Xu BPG II 23223; • Ledong County, Jianfengling National Nature Reserve, 18°43'15.09"N, 108°49'54.31"E, alt. 535 m, 02 Nov 2023, M.Y. Zhou, J.X. Liu & Z.C. Xu BPG II 23243; • ibid., 18°42'21.02"N, 108°52'6.03"E, alt. 826 m, 02 Nov 2023, M.Y. Zhou, J.X. Liu & Z.C. Xu BPG II 23238; ibid., 118°42'0.42"N, 08°51'52.07"E, alt. 753 m, 19 Jun 2024, M.Y. Zhou, J.X. Liu & Y.J. Chen CYJ2024029 (with fl.); • ibid., 18°40'57.61"N, 108°52'46.39"E, alt. 640 m, 19 Jun 2024, M.Y. Zhou, J.X. Liu & Y.J. Chen CYJ2024032 (with fl.); • ibid., 18°43'22.15"N, 108°50'3.24"E, alt. 633 m, 21 Aug 2024, M.Y. Zhou, J.X. Liu & Y.J. Chen CYJ2024052; • Qiongzhong County, Shipo Village, 18°51'59.97"N, 109°45'52.25"E, alt. 316 m, 4 Nov 2023, M.Y. Zhou, J.X. Liu & Z.C. Xu BPG II 23259; • Sanya City, Tianya District, Ming Shan, 26 Aug 2018, J.X. Liu & Z.C. Xu Liujx18079, Liujx18081; • Sanya City, Tianya District, Ya Lin, 27 Aug 2018, J.X. Liu & Z.C. Xu Liujx18084, Liujx18088.

Note.

Melocalamus utilis and M. orenudus were initially described as independent species of Dinochloa by McClure (1940). Based on molecular phylogeny, Liu et al. (2023) transferred them into Melocalamus. Phylogenetically, one sampled individual of M. utilis mixed into one clade which made M. orenudus paraphyletic in dd-RAD tree (Liu et al. 2023). We sampled more individuals in the Skmer analysis and resulted in a similar topology. Melocalamus utilis and M. orenudus exhibit high morphological similarity. Furthermore, these two species occupy overlapping distribution ranges, with type specimens collected from the similar location as “Lingshui Dist., Chim Shan, Fan Maan Ts’uen”, in Hainan Province (the type locality now belongs to Sandao Zhen of Baoting County, Fanna Village to Shougong Jianlin). Based on morphological and genetic evidence, as well as geographical distribution data, we conclude that M. utilis and M. orenudus are conspecific. Since both names were simultaneously published by the same author in the original work and no explicit choice of priority was made (McClure 1940), we propose to treat M. utilis as a synonym of M. orenudus following the International Code of Nomenclature (ICN) (Turland et al. 2025).

In October 2023, we collected a few flowering individuals of M. orenudus in Jianfengling National Nature Reserve, Hainan. We conducted follow-up investigations in this area in June and August 2024, respectively. In total, we found two clumps of M. orenudus in the flowering stage that were relatively close to each other and collected three flower-bearing specimens (BPG II 23238, CYJ2024029 and CYJ2024032). The descriptions of inflorescence are mainly based on the specimen BPG II 23238, which provided the epitype (designated here) of the species.

Neomicrocalamus prainii (Gamble) Keng f.

Chinese name. “新小竹” (xīn xiǎo zhú).

Neomicrocalamus prainii (Gamble) Keng f., J. Bamboo Res. 2(2): 10 1983.

≡ Microcalamus prainii Gamble, J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 59(2): 207, pl. 7. 1891 (1890).

≡ Arundinaria prainii (Gamble) Gamble, Ann. Roy. Bot. Gard. (Calcutta) 7: 21 1896.

≡ Thamnocalamus prainii (Gamble) E.G. Camus, Bambusées: 54 1913.

≡ Racemobambos prainii (Gamble) Keng f. & T.H.Wen, J. Bamboo Res. 5(2): 13 1986.

= Melocalamus gracilis W. T. Lin, J. South China Agr. Univ. 14(3): 100, 1993. nom. illeg. [Its later homonym of Melocalamus gracilis R.B. Majumdar in S. Karthikeyan et al. Fl. Ind. ser. 4, 1 (Monocotyledon): 278. 1989. Type: INDIA • Barail Range, near Kailana, 9 km from Gumrirest house on Shillong, Cachar Road near P.W.D. Shed; R.B. Majumdar 1138 (holotype, CAL, not seen)] ≡ Melocalamus ningmingensis Ohrnb. in D. Ohrnberger Bamb. World Introd. ed. 4: 19, 1997, syn. nov.

Type.

India • Assam: Naga Hills, 23 Apr 1886, alt. 2400 m, Dr. D. Prain s.n. (holotype, K!, Barcodes: K000246157; isotypes, K!, Barcodes: K000872509, K000872510, K000872511, K000872512; isotype, BM!, Barcode: BM000959211). China • Guangxi: Chongzuo City, Ningming County, Longrui, 1 Nov 1985, Feipeng Chen 4726 (holotype, CANT!, Barcode: 25005).

Note.

Melocalamus ningmingensis has a complex taxonomic history. Combining the Skmer analysis and morphological comparisons, we conclude that Feipeng Chen 4726 belongs to Neomicrocalamus prainii rather than Melocalamus.

Melocalamus guangxiensis D.Z. Li & J.X. Liu, sp. nov.

urn:lsid:ipni.org:names:77364890-1
Fig. 7 Chinese name. “广西梨籐竹” (ɡuǎnɡ xī lí téng zhú).

Type.

China • Guangxi: Chongzuo City, Ningming County, Chengzhong Town, Shanghe Village, 22°11'54.10"N, 106°58'41.96"E, alt. 163 m, 11 Apr 2023, Z.C. Xu et al. Xuzc2023109 (holotype, KUN!, Barcode: 1643898; isotype, CSH!, Barcode: CSH0219482).

Diagnosis.

Melocalamus guangxiensis resembles M. puberulus, M. cordatus, M. pacoensis, M. truongsonensis and M. compactiflorus var. fimbriatus in the characters of foliage leaf auricles with radiate oral setae or culm leaf ligules with fringed long setae at the apex. However, M. guangxiensis can be easily distinguished by its unique culm sheaths, which feature a membranous projection on the basal outer margin, ca. 1–2 cm and culm leaf blades that are long- lanceolate, non-constricted at the base.

Description.

Perennial. Rhizomes pachymorph, short-necked. Culms slender, ca. 10–15 m long, 1–2 cm in diam.; internodes greyish-green, with densely white-brown pubescence, hollow, 50–80 cm long, wall 3–5 mm; nodes prominent, a ring of light-brown tomenta present above and below nodes; sheath scars prominent, corky, with residual base of culm leaf sheaths. Buds solitary, triangle, puberulent, the lateral edges ciliolate. Branches several, slender and equal length, dominant one equal to culm in size. Culm leaves tardily deciduous, ca. 2/5 to 1/2 as long as the internodes, 20–30 cm long, base 15–20 cm wide; sheaths leathery, long-triangle, apex concave or truncated, margins thin, membranous, with white powder and brown hairs abaxially, base of outer one with a subcircular projection, ca. 1–2 cm; auricles wavy, narrow rim, with several fimbriate long oral setae, easily dropped; ligules prominent, 2–3 mm in length, uniformly serrated, with fimbriate hairs, 7–14 mm long; blades length 6–8 cm × width 0.7–0.9 cm, lanceolate, erect or recurved. Foliage leaves 6–12 per ultimate branch; sheaths leathery, glabrous; auricles reflexed, sickle-shaped, oral setae radiated, 6–12 mm long; ligules ca. 3 mm in length, with white short hairs abaxially, apex truncate or with inconspicuous serrated, with fimbriate long hairs, ca. 1 cm long; blades lanceolate, 16–26 cm × 3–4.5 cm, with white pubescence abaxially, one margin entire, the other with short cilium, secondary veins 10–12 paired. Inflorescence and caryopsis unknown.

Figure 7. 

Melocalamus guangxiensis D.Z. Li & J.X. Liu A. Habitat; B, C. Branch complement; D. Culm leaf blade; E. A complete internode and culm leaf, showing the culm bud, apex of culm leaf sheath and the base of culm leaf sheath; F. Longitudinal section of main culm; G, H. Foliage leaves and foliage leaf sheath; I. Branchlet.

Phenology.

New shoots May to August.

Distribution and ecology.

This new species is found in Pingxiang and Congzuo Counties in Guangxi, China. It grows in warm and humid environments and usually occurs in limestone montane areas at altitudes of 100–300 m.

Etymology.

The epithet originates from Guangxi Autonomous Region where the new species was collected.

Additional specimen examined.

China • Guangxi: Chongzuo City, Pingxiang County, Xiashi Town, Pochatun, 22°11'7.14"N, 106°58'3.98"E, alt. 260 m, 21 Jul 2023, C. Zhang et al. PX001.

Note.

In the Skmer tree, sampled individuals of Melocalamus guangxiensis clustered in a clade sister to M. putaoensis. Due to notable morphological differences between M. putaoensis and M. guangxiensis, such as the absence of culm leaf auricles and oral setae, ligules without cilia and the base of outer margin in culm leaf sheaths without a membranous projection in M. putaoensis, we conclude that this species belongs to Melocalamus, but does not fit into any described species. Therefore, we treat it as a new species of Melocalamus.

Remaining taxonomic problems

Melocalamus fimbriatus Hsueh & C.M. Hui was first described in 1992 (Hui and Hsueh 1992) and was subsequently treated as a variety of Melocalamus compactiflorus in 2001 (Guo and Li 2001). Our phylogenetic result aligns with the topology constructed by Liu et al. (2023) using ddRAD-seq datasets, demonstrating that Melocalamus compactiflorus var. fimbriatus does not cluster within the same clade with M. compactiflorus, thereby suggesting a relatively distant genetic relationship between these two taxa. Furthermore, besides the differences noted by Guo and Li (2001) in the length and shape of the culm leaf ligules between these two taxa, we have also observed significant differences in their culm leaf auricles and other morphological characters. Currently, due to material limitations, only a single specimen of M. compactiflorus has been included in our Skmer analysis, thus, the phylogenetic position of this species needs further validation through expanded sampling efforts involving additional individuals. Subsequently, we will conduct further research to confirm the taxonomic status of M. compactiflorus var. fimbriatus.

Maclurochloa K.M. Wong (Wong 1993) represents one of the bamboo genera distributed in Southeast Asia that exhibit climbing habits and possess a prominent branch. This genus differs from both Melocalamus and Dinochloa mainly in caryopsis type. Currently, four species have been formally described within this genus: Maclurochloa locbacensis H.N. Nguyen & V.T. Tran (Nguyen and Tran 2014), Maclurochloa montana (Ridl.) K.M. Wong (Wong 1993), Maclurochloa tonkinensis H.N. Nguyen & V.T. Tran (Nguyen and Tran 2013) and Maclurochloa trangdinhensis H.N. Nguyen & V.T. Tran (Tran and Nguyen 2019). Upon reviewing relevant literature, we found that Maclurochloa shares high morphological similarities with certain Melocalamus species, most notably characterised by nodes covered with white powder and lanceolate pseudospikelets, gradually pointed at the apex. Moreover, we observed substantial morphological similarity between Maclurochloa trangdinhensis and Melocalamus scandens, both of them possessing culm leaf blades that are either equal in length or longer than the culm leaf sheaths and the junction between the blades as well as the sheaths being oblique. In addition, preliminary molecular studies implied that Maclurochloa montana fell into the BDG complex (Goh et al. 2010; Zhou et al. 2017), but the relationships with Melocalamus and Soejatmia K.M. Wong remain to be resolved. It is necessary to conduct more in-depth study on the phylogenetic relationship between the two genera, based on morphological and molecular data.

Acknowledgements

We are grateful to Dr. Gang Yao and Mr. Ming-Xuan Zheng at South China Agricultural University (CANT) for providing valuable materials from the type specimen of Melocalamus ningmingensis and Mr. Jun-Sheng Wu at Sichuan Agricultural University for providing critical images from the type specimen of M. elevatissimus. We thank the staff at Jianfengling National Nature Reserve for their assistance in sample collection and Mr. Chao Zhang for providing pictures of M. guangxiensis. Ji-Feng Long, Shi-Xin Nong, Zhao-Ming Wang and Wen-Wu Ma from Guangxi Nonggang National Nature Reserve also provided valuable assistance during our field work. We express our gratitude to the Germplasm Bank of Wild Species and Molecular Biology Experiment Center at the CAS Kunming Institute of Botany for facilitating our work.

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 supported by the National Natural Science Foundation of China (32300206 and 32120103003) and the Yunnan Revitalization Talent Support Program “Young Talent” Project.

Author contributions

Yu-Jin Chen and Mei Chen conducted data analyses and drafted the manuscript. Jing-Xia Liu, Meng-Yuan Zhou and De-Zhu Li conceived, wrote and revised the paper. Zu-Chang Xu and Yu-Xiao Zhang revised the paper. All the authors participated in the field investigations.

Author ORCIDs

Yu-Jin Chen https://orcid.org/0009-0003-3191-5078

Mei Chen https://orcid.org/0009-0004-0802-3669

Meng-Yuan Zhou https://orcid.org/0000-0003-1492-8494

Zu-Chang Xu https://orcid.org/0000-0001-7431-1061

Yu-Xiao Zhang https://orcid.org/0000-0003-0602-3118

Jing-Xia Liu https://orcid.org/0000-0003-4205-6400

De-Zhu Li https://orcid.org/0000-0002-4990-724X

Data availability

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

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Supplementary materials

Supplementary material 1 

Additional information

Yu-Jin Chen, Mei Chen, Meng-Yuan Zhou, Zu-Chang Xu, Yu-Xiao Zhang, Jing-Xia Liu, De-Zhu Li

Data type: xlsx

Explanation note: table S1. Voucher information and sources of samples. table S2. The sequencing quality of samples.

This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
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Supplementary material 2 

The tree topology of the sampled Melocalamus with its related groups, based on the Skmer analysis

Yu-Jin Chen, Mei Chen, Meng-Yuan Zhou, Zu-Chang Xu, Yu-Xiao Zhang, Jing-Xia Liu, De-Zhu Li

Data type: jpg

Explanation note: The tree topology of the sampled Melocalamus with its related groups, based on the Skmer analysis (without plastid and mitochondrial reads). Coloured boxes indicate the doubtful species and the species names in parentheses indicate the corresponding names before being revised in this study. Types of generic names are in bold.

This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
Download file (11.00 MB)
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