Corresponding authors: Chao Hu (
Academic editor: Timothée Le Péchon
A new orchid species,
Wang Z, Zhang Y, Zhang Z, Li X, Wu Z, Yan L, Lu A, Xie C, Hu C, Huang W (2022)
The genus
During our field surveys in Xishuangbanna, Yunnan, China, an unknown species was found. In this paper, we analysed the morphological differences of the newly-found species and its allied species and the phylogenetic position of the new entity is also discussed, based on molecular evidence from nrITS and plastid
Materials of the new species were collected from Xishuangbanna, Yunnan, China during a field expedition. Morphological characters were observed, measured and photographed based on five living individuals under a stereomicroscope (SZX16-6151, Olympus, Japan) and photographed with a digital camera (D750, Nikon, Japan). A voucher specimen, designated as the holotype, was deposited at
Shanghai Chenshan Herbarium (
DNA sequences of nrDNA ITS and plastid
Taxon sampling in this study.
Species Name | nrITS |
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DNA sequences were aligned using the MAFFT programme in Geneious v. 2020.2.4 (
The length of nrITS matrix was 792 bp including 262 parsimony-informative sites and for
Maximum Likelihood tree of
The phylogenetic analyses indicate that
China. Yunnan Province (云南), Xishuangbanna (西双版纳), Mengla County (勐腊县) epiphyte on the tree trunk, 1620 m elev., 23Nov 2021, Zhengwei Wang, Xiaochen Li, Yu Zhang& Zhijin Wu, WZW04247 (holotype:
Morphology of
Epiphytic herbs. Roots slender, flexuose. Pseudobulbs clustered, ovoid-fusiform, slightly compressed laterally, 1–2 × 0.5–1 cm, upper half with 4–5 widely spaced leaves. Leaf blade ovate-oblong, 1.8–2.3 × 0.8–1.2 cm, apex acuminate, base contracted into a short petiole, articulate, margins of their apical half slightly crispate. Peduncle 7–10 cm long, with several sterile bracts 2–5 mm long; raceme with 7–10 flowers arranged in zigzag manner. Floral bracts broadly ovate with cordate base, 2–3 × 1–1.5 mm, acute. Flowers greenish-orange; pedicel and ovary ca. 7 mm long. Dorsal sepal broadly ovate with cordate base, 3.2–5 × 3–3.6 mm, 1-veined, abaxially carinate, apex acute; lateral sepal oblong-ovate or ovate-lanceolate, 5–6 × ca. 0.6 mm long, abaxially slightly carinate. Petals narrowly linear, 3–4 × ca. 0.2 mm; lip elliptic, 2–3 × ca. 1 mm, apex apiculate, base bearing a bituberculate callus, then expanded on each side into a thickened, folded, rounded lobe, with 1 excavation with raised margins between the lobes. Column straight, ca. 2 mm long, with a pair of subtriangular, obtuse wings on each side near the middle and a ridge on the back of the column. Anther cap hemispherical, pale yellow; pollinia 4 in 2 pairs with one pollinium of each pair smaller than the other, waxy, brownish, with minute apical viscidium.
Phenology: Flowering in November–December.
It is found on tree trunks on a limestone ridge-top evergreen broad-leaved forest at an elevation of 1500–1700 m in Mengna County, Xishuangbanna Autonomous Prefecture, Yunnan Province, People’s Republic of China. The habitat presents a tropical monsoon climate.
The species epithet refers to the large and conspicuous dorsal sepal of the flower.
Comparison of
Characters |
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Pseudobulbs | oblong or cylindrical-fusiform 5–9 3–5 mm | ovoid, 8–10 mm long | ovoid-fusiform, slightly compressed 1.5–2.5 cm × 6–10 mm | subcylindrical or ± spindle-shaped, 1.8–5 cm × 3–6 mm | ovoid-fusiform, slightly compressed, 1–2 cm × 0.5–1 cm |
Leaf | 2 or 3, margin flat | 3 or 4, strongly crisped-margined | 3 or 4, apical half slightly crisped-margined | 3 or 4, margin slightly serrate | 4 or 5, apical half slightly crisped-margined |
Scape | 2–5 cm, several to 10-flowered, flowers white | 5–10 cm long, with 10–15 flowers, flowers yellow, | 10–13 cm, more than 10-flowered, flowers orange | 7–18 cm, 10–50-flowered, flowers pale green or greenish-yellow | 7–10 cm, more than 10-flowered, flowers greenish-orange |
Bracts | ovate-lanceolate, 2–3 mm | ovate-lanceolate, 1.5–3.5 mm | lanceolate, 2–3 mm | lanceolate, 3–5 mm | broadly ovate, 2–3 mm |
Dorsal sepal | ovate-oblong, 2.5–3 × 1.5–1.8 mm | oblong-lanceolate, 3–4 × 0.8–1 mm | narrowly ovate-oblong, 4.8–5.8 × ca. 1.6 mm | oblong or elliptic-oblong, ca. 4 × 1.8 mm | broadly ovate, ca. 3.2–5 ×3–3.6 mm |
Petals | narrowly linear-lanceolate, 2.5–3 × ca. 0.5 mm, entire | narrow linear, 4–5 mm long, Y-shaped | narrowly linear, 5–5.5 × ca. 0.7 mm, entire | narrowly linear, ca. 3.5 × 0.3 mm, entire | narrowly linear, 3–4 × ca. 0.2 mm, entire |
Lip | broadly elliptic or orbicular, ca. 2.5 mm, base with an orbicular, auriculate, callus-shaped fold on either side, with a concave callus near base | epichile broadly oblong or subsquare, 1.5–2 × 1–1.5 mm, base with two auricles on both sides; claw short, with a fleshy callus centrally near base | broadly obovate-oblong, ca. 4 × 2.7 mm, with two callus-shaped thickened folds, two suborbicular lobes on both sides, centrally with one concave callus near base | broadly elliptic-oblong or broadly ovate-oblong, 2.5–3 mm, with two lateral splits below middle; two suborbicular lobes, centrally with one bilobed callus near base | broadly elliptic, ca. 2–3 mm long, two callus-shaped and thickened folds, base with two oblong lobes on both sides, centrally with one bituberculate callus near base |
Column | ca. 2.2 mm, two pairs of wings | ca. 1.5 mm, broadly winged with two horn-like appendages | ca. 2 mm, two pairs of wings | ca. 2.8 mm, a pair of wings, each with a retrorse thread | ca. 2 mm, a single pair of subtriangular wings |
The new species was found in a ridge-top evergreen broad-leaved forest on a limestone mountain. Despite numerous surveys in the areas, only six mature individuals were found without fruits or evidence of cross-pollination.
This extremely small effective population occurs in a touristic zone which is a serious threat to the survival of the species. Consequently, the species can be assessed as Critically Endangered (CR, D), based on current information and following IUCN guidelines (
This study was supported by grants from the National Wild Plant Germplasm Resource Centre for Shanghai Chenshan Botanical Garden (ZWGX2102), the Science and Technology Commission, Shanghai Municipality (19390743600) and the project of Shanghai Landscaping and City Appearance Administrative Bureau (G192424, G202401). We are grateful to Mingzhong Huang for his help with the literature and Hongjin Wei for his fieldwork. We are grateful to Dr. Pankaj Kumar for his help in improving the language and describing the conservation status. We are also grateful to the reviewers for their valuable views in improving this article.