Research Article |
Corresponding author: Bo Xu ( xubo@cib.ac.cn ) Academic editor: Timothée Le Péchon
© 2022 Min Liao, Yue-Hong Cheng, Jun-Yi Zhang, Yu Feng, Gui-Ying Liu, Ping Ye, Sen-Long Jin, Hong-Qiang Lin, Bo Xu.
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:
Liao M, Cheng Y-H, Zhang J-Y, Feng Y, Liu G-Y, Ye P, Jin S-L, Lin H-Q, Xu B (2022) Gastrochilus heminii (Orchidaceae, Epidendroideae), a new species from Sichuan, China, based on molecular and morphological data. PhytoKeys 215: 95-106. https://doi.org/10.3897/phytokeys.215.91061
|
Gastrochilus heminii (Orchidaceae), a new orchid species from Sichuan Province, Southwest China, is described and illustrated. It morphologically resembles G. affinis and G. yei, but differs markedly from the former in having a thinner and slightly rolled downwards reniform epichile and the central thickened purple-red mat with irregular folds (vs. subtriangular epichile curves upwards, with 2 thick, brown to purplish-brown median ridges from base to apex), and can be clearly distinguished from the latter by having reniform epichile with lobed apex and subconical hypochile with bilobed apex that splits into two conical protrusions (vs. semi-rounded epichile not lobed and subconical hypochile not bilobed). The results of molecular phylogenetic analysis based on nuclear ribosome internal transcribed spacer (nrITS) and four chloroplast DNA fragments (matK, psbA-trnH, psbM-trnD, and trnL-F) of 36 Gastrochilus species showed that G. heminii was closely related to G. affinis and G. distichus.
Gastrochilus, morphological, Orchidaceae, phylogeny, taxonomy
Gastrochilus D.Don (Orchidaceae, Epidendroideae;
An unusual arboreal miniature orchid was recently discovered for the first time in Wolong Nature Reserve (Wenchuan County, Sichuan Province, China) during a routine survey. It was tentatively identified as a species of Gastrochilus sect. Microphyllae Bentham & Hooker (
The measurements and description of Gastrochilus heminii were based on two living plant individuals and two herbarium specimens (voucher information: Min Liao & Yue-Hong Cheng ZJY143; Min Liao & Yue-Hong Cheng ZJY167), respectively. The taxonomic description follows the terminology used by
The sequences of the two individuals of the new species newly generated in this study, and the sequences of the remaining 42 species used in the molecular phylogenetic analysis, were retrieved from GenBank. The information on the DNA fragments and four complete plastid genomes were listed in Appendix
All sequences were edited via Sequencher v4.1.4 (Gene Codes, Ann Arbor, Michigan, USA) and aligned via MAFFT v7.475 (
The molecular phylogenetic tree showed that the 36 taxa of Gastrochilus formed a well-supported monophyletic group (BI/ML = 1/97, Fig.
Morphologically, G. heminii is closest to G. affinis and G. yei JianW.Li & X.H.Jin (
Morphological comparison of Gastrochilus heminii with three related species, G. affinis, G. distichus and G. yei.
Character | G. heminii | G. affinis | G. distichus | G. yei |
---|---|---|---|---|
Plant length | 3.0–6.5 cm | 4.0–15.0 cm | 1.5–20.0 cm | 3.0–8.0 cm |
Leaf shape | narrowly oblong or falcate oblong | oblong-lanceolate to subspathulate | lanceolate or falcate lanceolate | blade lanceolate |
No. of flowers per inflorescence | 1 or 2 flowers | 1–4 flowers | 2–4 flowers | 2–6 flowers |
Peduncle length | 0.4–0.7 cm | 1.5–2.0 cm | 1.0–1.5 cm | 0.7–1.0 cm |
Dorsal sepal | elliptic-oblong, ca. 2.4 × 1.5 mm, concave, apex obtuse | elliptic-oblong, 3–5 × 1–1.3 mm, concave, apex obtuse | oblong-elliptic, 4.5–0.5 × 2.5–3 mm, concave, apex obtuse | oblong, 3.3 × 1.9–2.0 mm, apex rounded |
Lateral sepals | similar to dorsal sepal, equal in size | elliptic-ovate, 3.5–4 × 0.7–1.3 mm, slightly oblique and incurved, apex obtuse | similar to dorsal sepal, equal in size | oblong, 3.9–4.0 × 1.8–1.9 mm, apex obtuse |
Petals | narrowly oblong, ca. 2.6 × 1.3 mm, apex acute, base narrowed | ovate-elliptic to elliptic, 3–4 × 1–1.3 mm, apex obtuse | subobovate, slightly smaller than sepals, apex obtuse | oblong, 3.5 × 1.8 mm, apex rounded |
Epichile | reniform, 4.2–6.5 × 2.0–3.0 mm, margin erose, smooth and glabrous above, central thickened purple-red mat with irregular folds | subtriangular, decurved, subacute at apex, margin finely erose at base, disk with 2 thick, brown to purplish-brown median ridges from base to apex. | subcircular, 5 × 3 mm, apex obtuse, margin entire, smooth and glabrous above and thickened cushion-like centrally, with 2 conical callosities near base | semi-rounded, 2.0–2.2 × 4.0–4.2 mm, glabrous, with a thicken central, rugose cushion, tint with purple, margin irregularly denticulate |
Hypochile | subconical or helmet-shaped, ca. 2–2.4 × 1.6–2 mm, dorsally compressed, slightly bent outward, the end splits into two conical protrusions | obconical, 3–4 × 2–3 mm, dorsally compressed, slightly bent outward, subacute to obtuse and shortly bifid at apex | subcupular, 4 × 2–3 mm, rounded at end, dorsally compressed, slightly bent outward | subconical, 3 mm tall, 3 mm in diameter, apex rounded |
Comparison of three taxa of Gastrochilus A, B Gastrochilus heminii C, D G. affinis E, F G. distichus G, H G. yei. [Images C, D cited from
China. Sichuan: Wenchuan, coniferous and broadleaf mixed forest, on tree trunk, elev. ca. 2640 m, in flowering and fruiting, 15 March 2022, Min Liao & Yue-Hong Cheng ZJY143 (holotype CDBI!).
Gastrochilus heminii is morphologically related to G. affinis and G. yei based on vegetative and floral characteristics such as similar habit, distichous and alternate leaves, epichile surface smooth and glabrous, sepals and petals with purplish-red patches. However, it can be differentiated from G. affinis on the basis of flower numbers (1–2 in the former vs. 1–4 in the latter), peduncle length (0.4–0.7 cm in the former vs. 1.5–2.0 cm in the latter) and an additional morphological characteristic: young leaves are densely covered with purple-red spots and old leaves have hardly any purple-red spots in the former (both have purple-red spots in the latter); the reniform epichile is rolled downwards, smooth and glabrous above, and central thickened purple-red mat with irregular folds in the former (subtriangular epichile curves upwards, with 2 thick, brown to purplish-brown median ridges from base to apex in the latter). It differs from G. yei by having reniform and lobed epichile (not lobed in the latter), apex of hypochile bilobed and splits into two conical protrusions (not bilobed in the latter), apex of the leaf with 1–2 lobules, lobes setaceous (apex of leaf with a tine in the latter).
Gastrochilus heminii A flowering plant B young leaves (B1: front view; B2: reverse view) C old leaves (C1: front view; C2: reverse view) D raceme and capsule (side view) E–I flowers (different views) J anatomy of flower (J1: dorsal sepals; J2 and J3: lateral sepals; J4 and J5: petals; J6: labellum) K hypochile (dorsal view) L stamens.
Miniature trunk epiphyte. Roots vermiform, 2.0–7.0 cm long and ca. 1.5 mm thick. Stem pendulous, slender, purplish-red spots, 3.0–6.5 cm long and ca. 1.8 mm thick. Leaves alternate, distichous, narrowly oblong or falcate oblong, 0.9–2.3 × 0.3–0.5 cm, apex acute and with 1–2 lobules, lobes setaceous, young leaves with conspicuous purplish-red spots, old leaves with hardly any purplish-red spots. Raceme with 1 or 2 flowers; inflorescence stalk curved upward and thickened, 4.0–9.0 mm long, proximally covered with two sheaths; floral bracts ovate-lanceolate, 0.7–1.0 mm long, apex acute; pedicel and ovary connate, 4.0–5.5 mm long; flowers spreading, ca. 6.0 × 5.0 mm; sepals and petals heterochromatic on both surfaces, outside yellow-green with purplish-red spots, inside purplish-red with yellow-green margin; dorsal sepals and lateral sepals similar and equal in size, elliptic-oblong, ca. 2.4 × 1.5 mm, apex obtuse; petals narrowly oblong, ca. 2.6 × 1.3 mm, apex acute, base narrowed; epichile reniform, yellow-green with purplish-red spots, 4.2–6.5 × 2.0–3.0 mm, margin erose, smooth and glabrous above, central thickened purple-red mat with irregular folds; hypochile subconical, yellow-green with purple-red spots, 2–2.4 × 1.6–2 mm, dorsally compressed, slightly bent outward, the apex splits into two conical protrusions; column cylindrical, ca. 1.0 mm; anther cap subhemispheric, with two chambers, 0.7 × 0.4 mm, hanging from both ends of the stipe; pollinia 2, 0.4 × 0.3 mm, yellow, full and nearly spherical, with a depression in the center; stigma deeply sunken, inverted V-shaped, ca. 0.6 mm long, yellow, apically forked, forked in a subtriangular outline. Capsule shuttle-shaped with six ribs, green with sparse purplish-red spots, ca. 1.1 cm long, inflated to ca. 0.6 cm in the middle, persistent and growing for one year until maturity.
—China. Sichuan: Wenchuan, coniferous and broadleaf mixed forest, on tree trunk, elev. ca. 2640 m, 18 April 2022, Min Liao & Yue-Hong Cheng ZJY167 (CDBI).
The new species is currently known only from Wenchuan County, Sichuan Province, Southwest China (Fig.
Named in honor of Mr. He-Min Zhang, the advocate of the panda “Release to the Forest”, one of the pioneers of panda research in China, renowned as the “father” of pandas, in recognition of his contribution to the conservation of flora and fauna in the region which was one of the earliest reserves dedicated to preserving the habitat of wild pandas. A Chinese name, he min peng ju lan (和民盆距兰), is suggested here.
Three populations with a total of ca. 200 individuals of Gastrochilus heminii have been documented during our investigation. However, similar habitat of this new species is widespread in the Wolong Natural Reserve. Therefore, we assessed the conservation status of Gastrochilus heminii as DD (Data Deficient) according to the
Our work was funded by the National Key Research and Development Program of China (Grant No. 2020YFE0203200), the Second Tibetan Plateau Scientific Expedition and Research (STEP) program (Grant No. 2019QZKK0502), 2022 Central Finance Forestry Grassland Ecological Protection and Restoration National Park Subsidy Project, 2022 Subsidy Projects of Prohibited Developmental Areas from the Transfer Payment of the National Key Ecological Functional Areas, and Wild Plants Sharing and Service Platform of Sichuan Province.
Taxa | nrITS | matK | psbA-trnH | trnL-F | psbM-trnD |
---|---|---|---|---|---|
G. acaulis (Lindl.) Kuntze | KM583455 | KM583465 | — | — | — |
G. acinacifolius Z.H.Tsi | KJ733412 | KJ733569 | KJ733492 | KJ733649 | MK357216 |
G. acutifolius (Lindl.) Kuntze | MT225573 | MW433889 | — | — | MK357230 |
G. affinis (King & Pantl.) Schltr. | — | MK357141 | — | — | MK357141 |
G. alatus X.H.Jin & S.C.Chen | — | — | — | — | MK357228 |
G. bellinus (Rchb.f.) Kuntze | KY966597 | KY966884 | MK357164 | MK357202 | MK357240 |
G. bigibbus (Rchb.f. ex Hook.f.) Kuntze | — | MN124439 | MN124439 | MN124439 | MN124439 |
G. calceolaris (Buch.-Ham. ex Smith) D.Don | MN517123 | MK357144 | MK357169 | MK357204 | MK357232 |
G. changjiangensis Q.Liu & M.Z.Huang | MK357124 | — | MK357166 | — | MK357236 |
G. ciliaris F.Maekawa | — | MK357148 | MK357173 | — | MK357225 |
G. dasypogon (Lindl.) Kuntze | DQ091685 | MK357149 | MK357181 | MK357197 | MK357219 |
G. deminutus J.M.H.Shaw | KY966600 | KY966887 | — | — | — |
G. distichus (Lindl.) Kuntze | KJ733414 | KJ733571 | KJ733494 | KJ733651 | — |
G. fargesii (Kraenzl.) Schltr. | KJ733415 | KJ733572 | — | KJ733652 | — |
G. formosanus (Hayata) Hayata | KJ733416 | KJ733573 | KJ733495 | KJ733653 | MK357226 |
G. fuscopunctatus (Hayata) Hayata | MK317970 | MK357150 | MK357171 | MK357192 | MK357231 |
G. gongshanensis Z.H.Tsi | — | MN124438 | MN124438 | MN124438 | MN124438 |
G. guangtungensis Z.H.Tsi | KJ733417 | KJ733574 | KJ733496 | KJ733654 | KJ733654 |
G. heminii M.Liao, B.Xu & Yue.H.Cheng | ON286752 | ON331126 | ON331128 | ON331130 | ON331132 |
G. heminii M.Liao, B.Xu & Yue.H.Cheng | ON286753 | ON331127 | ON331129 | ON331131 | ON331133 |
G. intermedius (Griff. ex Lindl.) Kuntze | MK357121 | MK357151 | MK357172 | MK357190 | MK357213 |
G. japonicus (Makino) Schltr. | KJ733418 | KF545886 | KF545866 | KF545897 | KX871236 |
G. linearifolius Z.H.Tsi & Garay | MK357133 | MK357136 | MK357187 | MK357194 | MK357229 |
G. linii Ormerod | — | MK357152 | MK357176 | MK357198 | MK357224 |
G. malipoensis X.H.Jin & S.C.Chen | — | MK357147 | MK357177 | MK357200 | MK357235 |
G. minutiflorus Aver. | — | MK357153 | MK357179 | — | MK357215 |
G. obliquus (Lindl.) Kuntze | MK357131 | MK357137 | KJ733498 | KJ733656 | MK357211 |
G. platycalcaratus (Rolfe) Schltr. | MK357122 | — | MK357175 | — | MK357222 |
G. pseudodistichus (King & Pantl.) Schltr. | MK357132 | — | MK357170 | — | MK357221 |
G. rantabunensis C.Chow ex T.P.Lin | — | MK357155 | MK357184 | MK357193 | MK357223 |
G. raraensis Fukuyama | KJ733420 | KJ733577 | KJ733499 | KJ733657 | MK357239 |
G. sinensis Z.H.Tsi | OM985813 | OK042953 | OK172399 | OK172401 | — |
G. somai (Hayata) Hayata | MK357128 | MN124436 | MK357180 | MN124436 | MK357220 |
G. tianbaoensis Q.Liu & Y.H.Tan | MK357120 | MK357157 | MK357186 | MK357207 | MK357214 |
G. wolongensis Jun.Y.Zhang, B.Xu & Yue.H.Cheng | OM985810 | OK172400 | OK172402 | OK172404 | OK172403 |
G. wolongensis Jun.Y.Zhang, B.Xu & Yue.H.Cheng | OM985811 | OM974209 | OM974211 | OM974210 | — |
G. yunnanensis Schltr. | MK165469 | MK357158 | MK357185 | — | MK357212 |
G. zhenyuanensis Q.Liu & D.P.Ye | MK357127 | MK357146 | MK357168 | MK357199 | MK357237 |
Holcoglossum amesianum (Rchb.f.) Christenson | HQ404389 | JF763779 | HQ404439 | — | — |
Holcoglossum kimballianum (Rchb.f.) Garay | HQ452901 | JF763787 | HQ404452 | — | — |
Luisia magniflora Z.H.Tsi & S.C.Chen | KJ733426 | KJ733583 | KJ733505 | — | KJ733663 |
Pomatocalpa diffusum Breda | AB217576 | AB217752 | — | — | EF670432 |
Pomatocalpa spicatum Breda | DQ091706 | KJ733595 | KJ733518 | — | KJ733675 |
Saccolabium pusillum Blume | AB217580 | AB217756 | — | — | — |