Research Article
Research Article
Gnetum chinense, a new species of Gnetaceae from southwestern China
expand article infoWei-Yin Jin§, Bing Liu§, Shou-Zhou Zhang|, Tao Wan|, Chen Hou, Yong Yang§
‡ Tonghua Normal University, Tonghua, China
§ Institute of Botany, Chinese Academy of Sciences, Beijing, China
| Shenzhen Fairy Lake Botanical Garden, Shenzhen, China
¶ Guangdong Academy of Forestry, Guangzhou, China
Open Access


Gnetum chinense sp. nov., a new lianoid species of Gnetaceae, is described from southwestern China. The new species is morphologically similar to G. montanum Markgr. in its oblong elliptic leaves and the ovoid to ellipsoid chlamydosperm, but differs from the latter by its shorter male spikes having fewer involucral collars (7–10 vs. 13–18 in G. montanum). We also did a new molecular analysis using one nuclear marker (i.e. nrITS) and four chloroplast markers (i.e. matK gene, rpoC1 intron, psbB-rps12 IGS, and trnF-trnV IGS). The result suggests that this specific clade is sister to a large clade consisting of all other known Chinese lianoid species of Gnetum except G. parvifolium (Warb.) W.C. Cheng.


Gnetum, China, morphology, phylogeny, taxonomy


Gnetum L., belongs to the monotypic family Gnetaceae of gymnosperms, and contains ca. 40 extant species that are widely distributed in tropical and subtropical forests in Asia, Africa and South America (Yang et al. 2017a). This genus is evergreen, mostly lianas, rarely trees, and possesses a set of unusual characters for gymnosperms, e.g. dicots-like broad leaves with pinnate venation, female gametophytes lacking archegonia, male and female reproductive units assembled into whorls, male spikes usually having abortive chlamydosperms and appearing to be bisexual, chlamydosperms possessing two outer envelopes, etc. (Pearson 1929; Maheshwari and Vasil 1961; Martens 1971; Gifford and Foster 1989; Friedman and Carmichael 1996). Although the earliest macrofossil of the gnetoid clade is known from the mid-Jurassic in northeastern China, the modern Gnetum is believed to diversify in South America and split into the New World clade and the Old World clade around the K-Pg boundary (Hou et al. 2015; Yang et al. 2017b). The Chinese clade diverged from other southeastern Asian species around 38 mya (million years ago, 95% posterior density 27–49 mya), and became more diversified after the earliest Miocene (ca. 21 mya, Hou et al. 2016).

Gnetum has a wide range of distribution in southern China (Cheng 1978; Fu et al. 1999). Cheng (1978) recognized seven species in China, while Fu et al. (1999) accepted nine species in the Flora of China. Both studies were based on herbarium material only. These traditional taxonomic treatments laid much emphasis on reproductive characters, but variation patterns of important reproductive characters are ambiguous because i) fruiting material is poorly represented in herbaria, and ii) it is difficult to match male and female specimens to a certain species when studying a dioecious taxon like Gnetum.

Molecular phylogeny was successfully applied to the delimitation of species of Gnetum in combination with morphological characters (Hou et al. 2016; Kim and Won 2016). Kim and Won (2016) applied a barcode method and recognized three species in Cambodia, i.e. G. macrostachyum Hook. f., G. montanum Markgr., and G. aff. gracilipes C.Y. Cheng. Hou et al. (2016) conducted a taxonomic revision based on molecular and morphological data, and recognized the following six lianoid species in China: G. catasphaericum H. Shao, G. formosum Markgr., G. luofuense C.Y. Cheng, G. montanum Markgr., G. parvifolium (Warb.) W.C. Cheng, and G. pendulum C.Y. Cheng.

A new Gnetum species was identified when we worked on a Gnetum genome project a few years ago. Further morphological and molecular studies on newly collected materials during field investigations in southern China allowed us to describe this species here as new to science.

Materials and methods

Plant materials, comprising silica-dried leaves and vouchers, were sampled in Yunnan and Guizhou of southern China. All vouchers were deposited in the Herbarium (PE), State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences (Table 1).

Table 1.

Sequences of Gnetum chinense sp. nov. generated in this study and their vouchers. All vouchers have been deposited in PE.

Collection Locality ITS matK rpoC1 psbB-rps12 trnF-trnV
T. Wan MLP001 China. Yunnan: Malipo. MT362085 MT373322 MT373311 MT373300 MT373333
T. Wan MLP002 China. Yunnan: Malipo MT373323 MT373312 MT373301 MT373334
T. Wan MLP003 China. Yunnan: Malipo MT373324 MT373313 MT373302 MT373335
T. Wan MLP005 China. Yunnan: Malipo MT373325 MT373314 MT373303 MT373336
B. Liu & al. 1360 China. Yunnan: Malipo MT362086 MT373326 MT373315 MT373304 MT373337
B. Liu & al. 1441 China. Yunnan: Malipo MT373327 MT373316 MT373305 MT373338
B. Liu & al. 1725 China. Yunnan: Malipo MT373328 MT373317 MT373306 MT373339
B. Liu & al. 2627 China. Yunnan: Cangyuan MT362087 MT373329 MT373318 MT373307 MT373340
B. Liu & al. 2675 China. Yunnan: Lancang MT362088 MT373330 MT373319 MT373308 MT373341
B. Liu & al. 3045 China. Yunnan: Jiangcheng MT362089 MT373331 MT373320 MT373309 MT373342
C.Y. Deng 12466 China. Guizhou: Xingyi MT362084 MT373321 MT373310 MT373299 MT373332

Total genomic DNA was extracted from the dried leaf materials using the CTAB method (Doyle and Doyle 1987) and purified using a QIAquick PCR Purification Kit. For phylogenetic studies, it is thought that nrITS and four chloroplast markers including matK gene, rpoC1 intron, psbB-rps12 IGS, and trnF-trnV IGS are highly variable and suitable for delimiting species of Gnetum (Kim and Won 2016; Hou et al. 2016). We followed the methods described in Hou et al. (2016), and one nuclear marker (i.e. nrITS) and four chloroplast markers (i.e. matK gene, rpoC1 intron, psbB-rps12 IGS, and trnF-trnV IGS) were targeted. Gnetum sequences generated in Hou et al. (2016) were downloaded from the GeneBank (Table 2). Sanger sequencing was conducted at Majorbio, Beijing, China. The output files were assembled and edited using Sequencer ver. 4.5 (Gene Codes Corporation, Ann Arbor, Michigan, U.S.A.) and DNA sequences were aligned using Clustal X ver. 2.1 (Larkin et al. 2007) and manually adjusted using BioEdit ver. 7.2.5 (Hall 1999). Sequences of the five markers were concatenated using SequenceMatrix Windows ver. 1.7.8 (Vaidya et al. 2011).

Table 2.

Gnetum sequences obtained from the GenBank for this study.

Species ITS matK rpoC1 psbB-rps12 trnF-trnV
G. catasphaericum_24 KX234206 KX234250 KX234304 KX234352 KX234382
G. catasphaericum_31 KX234205 KX234249 KX234303 KX234351 KX234381
G. catasphaericum_32 KX234203 KX234247 KX234301 KX234349 KX234379
G. catasphaericum_44 KX234202 KX234246 KX234300 KX234348
G. catasphaericum_33 KX234204 KX234248 KX234302 KX234350 KX234380
G. cuspidatum_20 KX234174 KX234222 KX234274 KX234325
G. cuspidatum_C52 KP256660 KP256698 KX234273 KX234324
G. diminutum_C101 KP256664 KP256702 KX234275
G. edule_C4 KP256658 KP256696 KX234268 KX234322
G. formosum_14 KX234200 KX234230 KX234298 KX234346 KX234377
G. formosum_21 KX234201 KX234231 KX234299 KX234347 KX234378
G. giganteum_37 KX234209 KX234252 KX234307 KX234354 KX234384
G. giganteum_41 KX234213 KX234256 KX234311 KX234358 KX234388
G. giganteum_8 KX234211 KX234254 KX234309 KX234356 KX234386
G. gnemon var. brunonianum_1 KX234173 KX234221 KX234265 KX234319
G. gnemon var. brunonianum_102 KX385188 KX385188 KX385188 KX385188
G. gnemon var. gnemon_2 KX234170 KX234219 KX234263 KX234317
G. gnemon var. gnemon_101 KX234171 KX385189 KX385189 KX385189 KX385189
G. gnemon var. griffithii_23 KX234172 KX234220 KX234264 KX234318
G. gnemonoides_C51 KP256656 KP256694 KX234266 KX234320
G. gracilipes_39 KX234210 KX234253 KX234308 KX234355 KX234385
G. gracilipes_42 KX234214 KX234257 KX234312 KX234359
G. hainanense_15 KX234184 KX234232 KX234283 KX234333 KX234364
G. hainanense_10 KX234195 KX234241 KX234293 KX234341 KX234373
G. hainanense_11 KX234193 KX234238 KX234290 KX234338 KX234370
G. hainanense_12 KX234194 KX234239 KX234291 KX234339 KX234371
G. hainanense_13 KX234198 KX234244 KX234296 KX234344 KX234375
G. hainanense_16 KX234199 KX234245 KX234297 KX234345 KX234376
G. hainanense_18 KX234196 KX234242 KX234294 KX234342
G. hainanense_25 KX234240 KX234292 KX234340 KX234372
G. hainanense_5 KX234197 KX234243 KX234295 KX234343 KX234374
G_hainanense_9 KX234192 KX234237 KX234289 KX234337 KX234369
G_hainanense_107 KX234187 KX385193 KX385193 KX385193 KX385193
G. hainanense_110 KX234186 KX385194 KX385194 KX385194 KX385194
G. latifolium_C15 KP256661 KX234269
G. leptostachyum_C102 KP256665 KP256703 KX234271
G. luofuense_19 KX234190 KX234236 KX234287 KX234336 KX234367
G. luofuense_27 KX234189 KX234235 KX234286
G. luofuense_28 KX234185 KX234233 KX234284 KX234334 KX234365
G. luofuense_6 KX234188 KX234234 KX234285 KX234335 KX234366
G. luofuense_C61 KX234191 KP256710 KX234288 KX234368
G. montanum_105 KX385195 KX385195 KX385195 KX385195
G. montanum_106 KX385196 KX385196 KX385196 KX385196
G. montanum_17 KX234208 KX234251 KX234306 KX234353 KX234383
G. montanum_29 KX234207 KX234305
G. neglectum_C19 KP256667 KP256705 KX234270
G. parvifolium_35 KX234178 KX234224 KX234277 KX234327
G. parvifolium_108 KX234176 KX385190 KX385190 KX385190 KX385190
G. parvifolium_109 KX234177 KX385192 KX385192 KX385192 KX385192
G. parvifolium_22 KX234181 KX234227 KX234280 KX234330
G. parvifolium_26 KX234180 KX234226 KX234279 KX234329
G. parvifolium_34 KX234179 KX234225 KX234278 KX234328
G. parvifolium_36 KX234175 KX234223 KX234276 KX234326
G. parvifolium_40 KX234182 KX234228 KX234281 KX234331
G. parvifolium_43 KX234183 KX234229 KX234282 KX234332
G. parvifolium_C50 KP256675 KX385191 KX385191 KX385191 KX385191
G. pendulum_103 KX385197 KX385197 KX385197 KX385197
G. pendulum_104 KX385198 KX385198 KX385198 KX385198
G. pendulum_38 KX234212 KX234255 KX234310 KX234357 KX234387
G. pendulum_4 KX234217 KX234260 KX234315 KX234362 KX234391
G. pendulum_45 KX234216 KX234259 KX234314 KX234361 KX234390
G. pendulum_46 KX234215 KX234258 KX234313 KX234360 KX234389
G. pendulum_47 KX234218 KX234261 KX234316 KX234363
G. raya_C11 KP256657 KX234267 KX234321
G. tenuifolium_C18 KP256662 KP256700 KX234272 KX234323
G. africanum_C41 KP256642 KP256681 KX234262

Previous studies suggested that the African species are sister to all Asian species (Won and Renner 2006; Hou et al. 2015), as a result, we chose the African G. africanum Welw. as the outgroup. Maximum likelihood (ML) analyses were conducted using the RAxM L-HPC2 on XSEDE (8.0.0) executed in the CIPRES portal (, Stamatakis 2014). The ML bootstrap values (BS) for each node were summarized after 1,000 replicates of bootstrapping iterations. The obtained trees were viewed and edited using FigTree ver. 1.4.0 ( Bayesian inference (BI) analyses were performed using MrBayes 3.2.6 (Huelsenbeck and Ronquist 2001) on XSEDE (8.0.0) in CIPRES. The Markov Chain Monte Carlo (MCMC) algorithm was run for 3,000,000 generations with the sampling frequency 1,000. Bayesian posterior probabilities (PP) were calculated for the majority consensus tree of all sampled trees after discarding trees sampled within the burn-in (25%) phase in MrBayes v.3.2.1.

The distribution map was generated using ArcGIS 9.3 (ESRI, Redlands, CA, USA; The photos were taken using digital cameras (Nikon D700 and Olympus TG-3), manually edited and created using Adobe Photoshop CS2 ver. 9.0. Phylogenetic trees were viewed and adjusted using FigTree ver. 1.4.0 (



The ML tree (Fig. 1), in general, was better resolved than the BI tree (Fig. 2). All Chinese lianoid taxa of Gnetum included in this study formed a strongly supported monophyletic group (BS: 100%; PP: 1.00). Ten samples of G. parvifolium constituted a sister group (BS: 100%; PP: 1.00) to a clade consisting of the rest of the lianoid congeners from China included in this study. The analyses revealed the 11 newly collected specimens as a monophyletic group (BS: 100%; PP: 1.00) sister to a clade composed of G. formosum, G. catasphaericum, G. luofuense, G. montanum and G. pendulum. Delimitations between G. montanum and G. pendulum were not resolved. The two samples of G. formosum formed a weakly supported group (BS: 81%; PP < 0.70), which was followed by a split between the strongly supported G. catasphaericum (BS: 98%; PP: 0.99) and a large clade containing a subclade of Gnetum montanum, G. pendulum, G. giganteum H. Shao, and G. gracilipes (BS: 98%; PP: 1.00), and another one of G. hainanense C.Y. Cheng ex L.K. Fu et al. and G. luofuense (BS: 98%; PP: 0.81). Delimitations between the two species were not resolved.

Figure 1. 

Maximum likelihood tree based on nuclear ribosomal ITS and chloroplast matK, rpoC1, psbB-rps12, and trnF-trnV, showing the robust species clade of Gnetum chinense sp. nov. Bootstrap values are displayed when they are greater than 50%.

Figure 2. 

Bayesian inference tree based on nuclear ribosomal ITS and chloroplast matK, rpoC1, psbB-rps12, and trnF-trnV, showing the robust species clade of Gnetum chinense sp. nov. Posterior probabilities are shown when they are greater than 0.70.


Gnetum chinense Y. Yang, Bing Liu & S.Z. Zhang, sp. nov.

Figs 3, 4


China. Yunnan: Cang-yuan County, on the way from Ban-hong to Ban-lao Prefecture, forest margin, male cones, March 31st, 2015, B. Liu, Y. Yang & T.W. Xiao 2627 (PE, holotype).

Figure 3. 

Map displaying the distribution of Gnetum chinense sp. nov. (black squares).


This species is similar to G. montanum in its oblong elliptic leaves and subsessile chlamydosperm, but differs from the latter by its shorter male cones (1–1.5 cm long in the new species vs. 2–3 cm in G. montanum) having fewer involucral collars (7–10 in the new species vs. 13–18 in G. montanum), nearly sessile or extremely shortly stiped chlamydosperms (vs. markedly stiped, stipes 3–5 mm long in G. montanum).


Lianas; twigs terete, dichasially branched having swollen nodes. Leaves opposite (Fig. 4a), oblong to elliptic, 11–16 cm long, 4–8 cm wide, base rotund to acute, apex acute to acuminate, pinnately veined, midvein impressed adaxially and elevated abaxially, lateral veins 6–8 (Fig. 4a), more or less elevated on both sides, petioles 1–1.2 cm long, grooved adaxially. Male reproductive shoots terminal, dichasial, branched once or twice (Fig. 4a). Male cones pedunculate, peduncles 2–10 mm long; cylindric, ca. 10–15 mm long, 4 mm in diam., involucral collars 8–10 (Fig. 4b). Chlamydosperms ellipsoid to subglobose, ca. 2.2 cm long, 1.4 cm in diam., apex obtuse, base contracted into an extremely short stalk or subsessile, green when young, and orange when mature (Fig. 4c).

Figure 4. 

Gnetum chinense sp. nov. A branch bearing male cones B male cones C female cone portion displaying chlamydosperm morphology.


In Yunnan and Guizhou provinces of China (Fig. 3).


In evergreen tropical and subtropical forests.


The specific epithet ‘chinense’ is derived from China.


Blooming male cones and mature chlamydosperms were found in late May and early November, respectively.


Gnetum chinense is common in evergreen forests in Yunnan and Guizhou. We consider this species to be of Least Concern (LC) under the IUCN Red List Categories and Criteria ver. 3.1 second edition (IUCN 2012).

Specimens examined

China. Yunnan: Lan-cang Lahuzu Autonomous County, from Shang-yun to Xi-meng, Apr. 2, 2015, B. Liu, Y. Yang & T.W. Xiao 2675 (PE); Jiang-cheng County, Qu-shui Prefecture, Apr. 18, 2015, B. Liu 3045 (PE); Ma-li-po County, March 15–17, 2015, T. Wan MLP001, MLP002, MLP003, MLP 005 (PE); Ma-li-po County, Xia-jin-chang Prefecture, Li-jia-wan, May 27, 2011, B. Liu 1360 (PE); Ma-li-po County, Xia-jin-chang Prefecture, Li-jia-wan, Sept. 24, 2011, B. Liu 1441 (PE); Ma-li-po County, Xia-jin-chang Prefecture, Li-jia-wan, Nov. 2, 2012, B. Liu 1725 (PE). Guizhou: unknown collection date, C.Y. Deng CYD12466 (PE).


Phylogenies based on molecular data have clearly resolved major lineages of Gnetum, including a South American clade, an African clade, and several Asian clades (Won and Renner 2003, 2005a, 2005b, 2006; Kim and Won 2016; Hou et al. 2015, 2016). Taxonomy of the Asian Gnetum is rather complicated because plants of the genus are usually dioecious woody climbers, and there are few taxonomic characters, so it is difficult to identify species without diagnostic reproductive characters (Kim and Won 2016).

Phylogenetic methods were successfully applied to discover and delimit species of Asian Gnetum (Kim and Won 2016; Hou et al. 2016). Our phylogenetic study found a new specific clade that was not recognized in previous studies; this clade is well resolved (Figs 1, 2; BS: 100%; PP: 1.00).

We did a morphological comparison between our new species and those known lianoid species from China (Table 3), and found that the specimens of this new specific clade are similar to G. montanum in the shape of leaves and chlamydosperms, and to G. parvifolium in the length of the male spikes and number of involucral collars, but differ from G. montanum by their shorter male cones having fewer involucral whorls, and from G. parvifolium by their larger leaves 11–16 cm long and bigger chlamydosperms ca. 2.2 cm long (vs. smaller leaves ca. 4–11 cm long, smaller chlamydosperms 1.3–1.8 cm long).

Table 3.

A morphological comparison between Gnetum chinense and other Chinese lianoid species.

Species Leaf blade shape Leaf blade length (cm) Leaf blade width (cm) Petiole length (mm) Male spike length (cm) Male spike involucral collars Chlamydosperm shape Chlamydosperm length (cm) Chlamydosperm stipe length (mm)
Gnetum catasphaericum H. Shao Ovate to oblong ovate 7–12 4–6.5 6–10 ca. 2 10–16 Oblong, subglobose 1.8–2.2 2–6
G. chinense sp. nov. Oblong to elliptic 11–16 4–8 10–12 1–1.5 8–10 Ellipsoid to subglobose ca. 2.2 Subsessile
G. formosum Markgr. Elliptic to narrowly oblong 11–14 4–7 9–10 ? ? Narrowly oblong, fusiform 2–2.5 Sessile
G. luofuense C.Y. Cheng Elliptic to oblong ovate 4.5–16 3–8.5 8–13 2–3 12–15 Broadly ellipsoid to cylindric 1.8–2.5 2–5
G. montanum Markgr. Elliptic to oblong 10–28 4.5–13 9–26 2–3.5 16–25 Cylindric ovoid, cylindric 1.6–2 3–5
G. parvifolium (Warb.) W.C. Cheng Elliptic to narrowly oblong 4–11 2–4 5–7 0.8–1.5 9–11 ellipsoid 1.3–1.8 Sessile
G. pendulum C.Y. Cheng Narrowly elliptic to oblong ovate 10–18 4–8.5 8–15 1–1.5 12–15 Elongate ellipsoid 3–4 10–30

A few morphological details of the new species are taxonomically important but not known to us, e.g. shape and the number of sterile ovules in male spike. As a result, further field investigations are encouraged.


We thank Mr. X.J. Guo for his kind help during the field investigation, Prof. Dr. David K. Ferguson for his help with English writing. We are also grateful to Dr. H. Won for his valuable suggestions on this new species.

This work was supported by the National Natural Science Foundation of China [31770211, 31470301, 31500165] and CAS International Research and Education Development Program (SAJC201613).


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