Research Article |
Corresponding author: Ying Tang ( sanxiaqutang@sina.com ) Academic editor: Vincent Droissart
© 2022 Xue-Man Wang, Ying Tang, Pei-Hao Peng, Hua Peng.
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:
Wang X-M, Tang Y, Peng P-H, Peng H (2022) Hemipilia avisoides (Orchidaceae), a new species from Sichuan Province, China. PhytoKeys 213: 1-18. https://doi.org/10.3897/phytokeys.213.90377
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A new orchid species, Hemipilia avisoides, is described from Songpan County and Maoxian County, Sichuan Province, China. Morphologically, H. avisoides is most similar to H. hui, but can be distinguished by the combination of its involute middle lip lobe that is smaller than the lateral lobes, floral bracts that are 5 mm long and are always shorter than the ovary, a leaf that is appressed to the substrate and is adaxially green with white lines along 7–9 principal veins and the subterranean stem with a solitary sheath at its base. The floral morphology of H. avisoides is presented by utilising in vivo micro-CT scanning and 3D visualisation.
Arid valley, Minjiang River Valley, Orchidinae, taxonomy
The genus Hemipilia Lindl. sensu stricto (Orchideae, Orchidaceae) comprises ca 10 species that are characterised by a protruding, tongue-like rostellum (
Given the fact that Ponerorchis Rchb.f. and Amitostigma Schltr. are paraphyletic to several taxa, including Hemipilia s.s.,
When transferring Ponerorchis limprichtii to Hemipilia sensu latissimo,
During the field trip in 2013 to collect Hemipilia physoceras (Schltr.) Y.Tang & H.Peng in Minjiang River Valley, Songpan County, Sichuan Province, China, one of the authors (Y. Tang) collected another orchid that morphologically fits into the category of Hemipilia sensu latissimo. It had been temporarily identified as Ponerorchis cf. limprichtii in the previous study by
During our field investigation to Minjiang River Valley, Songpan, Sichuan, China in 7–9 June 2022, two populations of the new taxon with 12 flowering individuals were found. One population (ZJG) occurs at the same locality that was visited in 2013 by one of the authors (Y. Tang) and the other (JPY) is ca 11.2 km southwards in the Valley.
One living individual from the ZJG population and three from the JPY population with intact flowers were collected, each was packaged with soils and EPE pearl cotton in a plastic bottle and transported by air to the Key Laboratory of Stratigraphy and Paleontology, Ministry of Natural Resources for in vivo micro-CT scanning. After scanning, these individuals were pressed and conserved as dried specimens.
The leaf material of one individual from the JPY population was collected and dried with silica gel for DNA sequencing.
To compare the new taxon with morphologically similar species, one population of Hemipilia hui in Kangding, Sichuan, China was investigated in 18 June 2022. The population was found under shrubs at the elevation of ca 3470 m. Five blooming individuals with intact flowers were observed, which showed some variations in morphology but generally fit well with the description in Flora of China (
All voucher specimens collected as part of this study were deposited at the Herbarium of Sichuan University (
The morphological description of the new taxon was mainly based on living materials. The length and width of leaves and the height of the inflorescence were measured on seven living, flowering plants in the field. The morphology of subterranean parts was described based on the four plants collected (see Material collection). The morphology of a single flower was described mainly based on the 3D mesh model reconstructed by micro-CT data.
X-ray Computed Tomography (CT) was completed at the Key Laboratory of Stratigraphy and Paleontology, Ministry of Natural Resources. The individual collected from the ZJG population (see Material collection) was finally selected for scanning and was then chosen as the holotype of the new taxon. Its inflorescence with the uppermost three flowers was scanned in vivo in a NIKON XTH 225ST CT scanner at a resolution of 18.6 μm and X-ray of 90 kV and 70 μA.
The 3D reconstructions were performed in the software VGSTUDIO MAX 3.0 with STL files being exported. For the 3D model of inflorescence, however, only the uppermost two flowers were reconstructed due to the trade-off between resolution and computing time. Acquired 3D mesh models were visualised and processed by the software GOM INSPECT PRO in GOM SUITE 3.1.1109.0.
Based on previous studies (
Genomic DNA extraction, primer synthesis, PCR reactions and Sanger sequencing were completed by Tsingke Biotechnology Co., Ltd. (Chengdu, China). Four DNA markers, including one nuclear (nrITS) and three plastid markers (matK, trnL-F and trnS-trnG), were used in this study. The primer pairs for these regions were 17SE/26SE (
Phylogenetic reconstruction was carried out using Bayesian inference (BI) and maximum likelihood (ML) analyses. Data for the plastid regions were combined, whereas the nrITS and combined plastid DNA datasets were analysed separately according to the results of
The best-fit models for BI are GTR+F+I+G4 (nrITS and matK) and GTR+F+G4 (trnL-F and trnS-trnG) and for ML analyses they are GTR+F+I+G4 (nrITS), K3Pu+F+R3 (matK), K3Pu+F+R2 (trnL-F) and K3Pu+F+G4 (trnS-trnG).
Partitioned BI analyses were conducted using MrBayes 3.2.7a (
The 3D mesh model of the uppermost two flowers on an inflorescence and photos of the corresponding micro-CT-scanned individual of Hemipilia avisoides are available on Zenodo via DOI: https://doi.org/10.5281/zenodo.6832154.
Trees reconstructed from the nrITS and combined plastid datasets in this study are similar to those of previous studies (e.g.,
Phylogenetic placement of Hemipilia avisoides sp. nov. in the Bayesian analysis of the nrITS dataset. Bayesian posterior probabilities (BPP) and maximum likelihood bootstrap supports (BSML) are displayed above and below the branches, respectively. Only BPP ≥ 0.95 and BSML ≥ 80 are considered as strong supports and are shown. The scale bar denotes the estimated number of substitutions in Bayesian analysis.
Phylogenetic placement of Hemipilia avisoides sp. nov. in the Bayesian analysis of the combined plastid dataset. Bayesian posterior probabilities (BPP) and maximum likelihood bootstrap supports (BSML) are displayed above and below the branches, respectively. Only BPP ≥ 0.95 and BSML ≥ 80 are considered as strong supports and are shown. The scale bar denotes the estimated number of substitutions in Bayesian analysis.
China, Sichuan Province, Aba Tibetan and Qiang Autonomous Prefecture, Songpan County, 9 June 2022, Y. Tang, X.-M. Wang & Y.-T. Zhu 235 (holotype:
Similar to Hemipilia hui (Tang & F.T.Wang) Schuit., from which H. avisoides can be distinguished by a set of characteristics: mid-lobe involute, suboblong in apical view, 2.2 × 1.2 mm, trapeziform when flattened, smaller than lateral lobes; floral bracts 5 mm long, always shorter than ovary; leaf appressed to the substrate, adaxially green with white lines along 7–9 principal veins; stem subterranean, with one sheath at the base (Table
Comparisons in morphology between Hemipilia avisoides sp. nov. and H. hui. Diagnostic characteristics of H. avisoides are in bold.
Species | Hemipilia avisoides | H. hui |
---|---|---|
Stem shape | Subterranean, with 1 sheath at the base | Partly subterranean, with 1 or 2 (or 3) sheaths at the base |
Leaf position | Appressed to the substrate | Sub-basal |
Leaf colour adaxially | Green with white lines along 7–9 principal veins, sometimes also with purple spots | Usually green with purple markings, sometimes green with white, reticulate venation or nearly uniformly green |
Flora bract shape | Elliptic, 5 mm long, always shorter than ovary | Lanceolate or ovate-lanceolate, lower ones nearly as long as ovary, gradually smaller upwards to shorter than ovary |
Dorsal sepal shape | Oblong, apex rounded, sometimes concave at each side of central vein below middle | Suboblong, apex subacute |
Lateral lip lobe shape | Pendulous, rhombic | Usually horizontal, auricular or transversely suboblong |
Middle lip lobe shape | Involute, suboblong in apical view, 2.2 × 1.2 mm, trapeziform when flattened, smaller than lateral lobes, apex rounded or sometimes apiculate | Usually open and flat, subsquare, 4–5 × 3–4 mm, larger than lateral lobes, apex obtuse-rounded, sometimes slightly emarginate or shortly apiculate |
Terrestrial, erect herbs, 8.5–31 cm tall. Tubers oblong, 2.5 cm long, 0.8 cm in diameter, neck with few roots. Stem subterranean, 2.7–5 cm long, 0.2 cm in diameter, with one sheath at the base. Sheath tubular, membranous, 1–2 cm long, pale yellow. Leaf appressed to the substrate, solitary, cordate, ovate or elliptic, 3–6.5 × 2–5.5 cm, apex acute, slightly fleshy, glabrous, abaxially purple, adaxially green with white lines along 7–9 principal veins, sometimes also with purple spots. Inflorescence terminal, erect, 3–14 cm long, 1–21-flowered, glabrous, dark purple. Flowers not secund, plum or purple plum, fragrant; floral bracts connivent to ovary, elliptic, 5 × 2.6 mm, shorter than ovary, apex acuminate, glabrous, dark purple; ovary curved, cylindrical, 10.5 mm long including pedicel, 1 mm in diameter, glabrous, dark purple. Dorsal sepal erect, oblong, cymbiform, 4.5 × 2.6 mm, apex rounded, sometimes concave at each side of central vein below middle, glabrous; lateral sepals spreading, obliquely ovate, cymbiform, 5.6 × 3.6 mm, apex obtuse, glabrous. Petals erect, connivent with dorsal sepal and forming a hood, apex bending similar to holding a fist in the other hand, obliquely ovate, 4 × 2.8 mm, apex obtuse, glabrous. Labellum spreading, broadly ovate when flattened, 7.1 × 5.4 mm, 3-lobed below middle, spurred, base collar-like raised on each side of spur entrance, glabrous, tinged white at base, disc dotted with purple; lateral lobes pendulous, rhombic, 3.4 × 2.5 mm, apex truncate, margin slightly undulate; mid-lobe horizontal, involute, suboblong in apical view, 2.2 × 1.2 mm, trapeziform when flattened, apex rounded or sometimes apiculate; spur horizontal, straight or curved upwards, cuneate, 9 mm long, ventrally carinate along central axis, entrance 2.5 mm wide, apex swollen, obtuse, 2.7 mm wide; anther reclined, 2.8 mm long, 2-locular, locules parallel and closely spaced, aubergine; pollinia 2, sectile, ovate, 1.2 × 0.7 mm; caudicles cuneate, 1.2 mm long; viscidia 2, closely spaced, oblong, transparent, each enclosed within a separate bursicle; bursicles formed by folding of rostellar arms, oblong, 0.6 × 0.3 mm; rostellum median lobe triangle, 0.7 mm long, lateral lobes grooved; stigma ventral, lobes 2, divergent, lamelliform, 1.2 × 0.5 mm, with hairs at base; auricles 2, each placed laterally at base of anther and behind collar of labellum base, 0.5 mm long.
Peaking in early June.
Hemipilia avisoides is currently known from two localities in Songpan County, which are ca 11.2 km apart along the Minjiang River Valley and one locality in Maoxian County according to the collection by S.-Y. Chen et al. in 1958. Individuals of the new taxon occur under arid-valley shrubs and on moss-covered rocks (see Discussion).
Latin avis, bird, and suffix -oides, similar, alluding to appearance of flower arrangement simulating flying birds with flapped wings.
雁字舌喙兰 (Chinese Pinyin: yànzì shéhuìlán).
Hemipilia avisoides: China, Sichuan Province, Aba Tibetan and Qiang Autonomous Prefecture, Songpan County, 30 June 2013, Y. Tang 151 (KUN!). Hemipilia hui: China, Sichuan Province, Ganzi Tibetan Autonomous Prefecture, Kangding City, 18 June 2022, Y. Tang, X.-M. Wang, W.-Q. Yuan & Y.-T. Zhu 237 (
Hemipilia avisoides seems narrowly distributed within the arid valley in the upper reaches of Minjiang River (see Discussion), with few populations and individuals being found. The habitat of H. avisoides could be easily disturbed by development as it is close to roads and villages. According to the IUCN Red List Categories and Criteria (
Floral morphology of Hemipilia avisoides sp. nov., based on 3D mesh model reconstructed by micro-CT data A inflorescence with uppermost two flowers B ventral and dorsal views of floral bract C lateral view of ovary, with floral bract at base D ventral and dorsal views of dorsal sepal E ventral and dorsal views of lateral sepal F ventral and dorsal views of petal G ventral view of gynostemium H ventral and dorsal views of labellum I lateral views of labellum. The 3D model in STL format is available on Zenodo (https://doi.org/10.5281/zenodo.6832154).
The new species Hemipilia avisoides has oblong tubers, two erect anthers, two stigmas that are beneath the rostellum and two sectile pollinia with viscidium each enclosed within a bursicle. These characteristics fit well into the category of Hemipilia sensu latissimo (
Molecular phylogenies did, however, reveal a close relationship between Hemipilia s.s. and H. avisoides in a clade (Figs
Amongst the specimens of Hemipilia hui, one collection by S.-Y. Chen et al. in 1958 caught our attention for it was gathered from Maoxian County at an elevation of 1780 m, this being close to the localities where we discovered H. avisoides. The environment of that region differs from the alpine habitat that H. hui usually favours. After careful examination, we believe that this specimen represents H. avisoides here described, although it was initially identified as H. hui. We highlighted in Fig.
According to the spatial delimitation of the arid valley in the upper reaches of Minjiang River (
The morphologically similar species Hemipilia hui is also distributed in Gansu Province, which is north of Sichuan Province. According to the vegetation regionalisation of China (
A few individuals of Hemipilia avisoides were observed in the field to possess conspicuously purple spots, along with white lines along 7–9 principal veins, on their leaves (Fig.
Our deepest gratitude goes to Dr Shou-Ming Chen from the Key Laboratory of Stratigraphy and Paleontology, Ministry of Natural Resources for his work in completing the micro-CT scanning and 3D model reconstruction of the new species. We are grateful to Prof Wen-Lan Feng and Mr Jie Zheng from Chengdu University of Information Technology for their help in evaluating whether the new species occurs in the arid valley in the upper reaches of Minjiang River. We are indebted to Dr Jin-Bo Tan from the Herbarium of Sichuan University, Dr Fei Zhao from Kunming Institute of Botany, Chinese Academy of Sciences, Dr Yang-Jun Lai from Institute of Botany, Chinese Academy of Sciences and Prof Zhao-Yang Chang and Prof Zhen-Hai Wu from Northwest A&F University for their help in checking herbarium specimens. We thank Ms Wen-Qin Yuan and Mr Yu-Tong Zhu from Chengdu University of Technology for their assistance during our field trips. This study was supported by the Special Project of Orchid Survey of National Forestry and Grassland Administration (contract no. 2019073016).
Voucher information and GenBank accession numbers of taxa included in phylogenetic reconstruction. Sequences generated in this study are marked with asterisks (*). Missing data are indicated with “–”.
Accession | Voucher/Reference | ITS | matK | trnL-F | trnS–trnG |
---|---|---|---|---|---|
Brachycorythis henryi |
|
MF944262 | MF945438 | MF945234 | – |
B. obcordata |
|
MF944263 | MF945500 | MF945301 | – |
Hemipilia alpestris |
|
KM651221 | KM651385 | KM651545 | KM651627 |
H. amplexifolia |
|
KM651222 | KM651386 | KM651546 | KM651628 |
H. avisoides [Tang 151] |
|
KM651296 | KM651462 | KM651621 | KM651699 |
H. avisoides [Tang, Wang & Zhu 236] | Tang, Wang & Zhu 236 | OP597820* | OP595696* | OP595697* | OP595698* |
H. basifoliata [Jin 8361] |
|
MF944399 | MF945455 | MF945251 | – |
H. basifoliata [Tang & Su 166] |
|
KM651223 | KM651387 | KM651547 | KM651629 |
H. brevicalcarata |
|
KM651285 | KM651449 | KM651611 | KM651689 |
H. calcicola |
|
KM651279 | KM651440 | KM651605 | KM651684 |
H. calophylla |
|
KM651269 | KM651433 | KM651595 | KM651674 |
H. camptoceras |
|
KM651275 | KM651439 | KM651601 | KM651680 |
H. capitata |
|
KM651224 | KM651388 | KM651548 | KM651630 |
H. cf. amplexifolia |
|
KM651225 | KM651415 | KM651549 | KM651631 |
H. cf. flabellata |
|
KJ460050 | KJ452806 | MF945327 | – |
H. chidori |
|
KM651287 | KM651451 | KM651612 | KM651690 |
H. chusua [Jin 8272] |
|
MF944401 | MF945460 | MF945257 | – |
H. chusua [STET 0619] |
|
KJ460034 | KJ452786 | MF945189 | – |
H. chusua [Tang & Su 093] |
|
KM651288 | KM651452 | KM651616 | KM651694 |
H. chusua [Tang 145] |
|
KM651290 | KM651453 | KM651615 | KM651693 |
H. compacta |
|
JN696455 | KJ452796 | MF945321 | – |
H. cordifolia |
|
MF944329 | MF945454 | MF945250 | – |
H. crassicalcarata |
|
KM651270 | KM651434 | KM651596 | KM651675 |
H. cruciata |
|
MF944330 | MF945462 | MF945259 | – |
H. cucullata |
|
KM651276 | KM651442 | KM651604 | KM651683 |
H. faberi [Tang 158] |
|
KM651229 | KM651391 | KM651553 | KM651635 |
H. faberi [Tang 161] |
|
KM651230 | KM651389 | KM651554 | KM651636 |
H. farreri |
|
KM651231 | KM651392 | KM651555 | KM651637 |
H. flabellata |
|
KM651271 | KM651435 | KM651597 | KM651676 |
H. forrestii |
|
KJ460049 | KJ452805 | MF945326 | – |
H. fujisanensis |
|
KM651280 | KM651444 | KM651606 | KM651685 |
H. galeata |
|
KT183499 | KT183498 | KT183500 | – |
H. gonggashanica |
|
KM651233 | KM651394 | KM651557 | KM651639 |
H. gracilis |
|
KM651235 | KM651397 | KM651559 | KM651641 |
H. graminifolia |
|
KM651294 | KM651458 | KM651619 | KM651697 |
H. hemipilioides |
|
KM651238 | KM651400 | KM651562 | KM651644 |
H. hui [Jin, Jin & Cui 14466] |
|
MF944398 | MF945425 | MF945220 | – |
H. hui [Tang 156] |
|
KM651297 | KM651463 | KM651622 | KM651700 |
H. hui [Tang 199] |
|
KM651298 | KM651461 | KM651623 | KM651701 |
H. keiskei |
|
KM651239 | KM651401 | KM651563 | – |
H. keiskeoides |
|
KM651240 | KM651402 | KM651564 | KM651645 |
H. kinoshitai |
|
KM651241 | KM651403 | KM651565 | KM651646 |
H. kiraishiensis |
|
MF944403 | MF945445 | MF945241 | – |
H. kwangsiensis |
|
KM651272 | KM651436 | KM651598 | KM651677 |
H. lepida |
|
KM651242 | KM651404 | KM651566 | KM651647 |
H. monantha [Tang & Jiang 171] |
|
KM651243 | KM651405 | KM651569 | KM651650 |
H. monantha [Tang 192] |
|
KM651244 | KM651407 | KM651567 | KM651648 |
H. monantha [Tang 193] |
|
KM651245 | KM651406 | KM651568 | KM651649 |
H. oblonga |
|
KM651281 | KM651445 | KM651607 | KM651686 |
H. omeishanica |
|
KM651299 | KM651464 | KM651624 | KM651702 |
H. parceflora |
|
KJ460052 | KJ452808 | KM651571 | – |
H. physoceras |
|
KM651248 | KM651410 | KM651573 | KM651654 |
H. pinguicula |
|
KM651250 | KM651413 | KM651576 | KM651657 |
H. purpureopunctata |
|
KJ460051 | KJ452807 | MF945328 | – |
H. secundiflora |
|
MF944406 | MF945458 | MF945254 | – |
H. sichuanica |
|
KJ460059 | KJ452815 | MF945334 | – |
H. simplex |
|
KM651253 | KM651416 | KM651578 | KM651659 |
H. tetraloba |
|
KM651255 | KM651418 | KM651580 | KM651661 |
H. thailandica |
|
KM651256 | KM651419 | KM651581 | KM651662 |
H. tibetica [Jin & Zhang 11075] |
|
MF944412 | MF945449 | MF945245 | – |
H. tibetica [Tang & Su 064] |
|
KM651257 | KM651421 | KM651582 | KM651663 |
H. trifurcata |
|
KJ460055 | KJ452811 | KM651583 | – |
H. wenshanensis |
|
KM651258 | KM651422 | KM651584 | KM651665 |
H. yajiangensis |
|
OM009240 | OM009241 | OM009241 | OM009241 |
H. yueana |
|
KM651259 | KM651423 | KM651585 | KM651666 |
Ponerorchis gongshanensis [Tang & Su 128] |
|
KM651226 | KM651395 | KM651550 | KM651632 |
P. nana [Jin 9138] |
|
MF944404 | MF945475 | MF945273 | – |
P. wolongensis [PS-00309] |
|
MZ098270 | – | – | – |