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| Gastrochilus balangshanensis Jun Y.Zhang, B.Xu & Yue H.Cheng,, in Zhang, Cheng, Liao, Jin, Lin, Yang, He et Xu, 2024. |
Abstract
Gastrochilus balangshanensis, a new orchid species from the Balang Mountain, Sichuan Province, Southwest China, is described and illustrated. It morphologically resembles G. affinis, but differs in having shorter stems, a reniform epichile and a sub-hemispherical hypochile (spur), obtuse-rounded at the apex. The results of molecular phylogenetic analyses based on nuclear ribosome internal transcribed spacer (nrITS) and four chloroplast DNA markers (matK, psbA–trnH, psbM–trnD and trnL–F) from 50 Gastrochilus species indicate that G. balangshanensis is closely related to G. heminii and G. bernhardtianus, also endemic to the Hengduan Mountains. The novelty is a branch and trunk epiphyte in mixed coniferous forest.
Key words: Hengduan Mountains, new species, phylogeny, Sichuan, Vandeae
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| Gastrochilus balangshanensis A habit B leaf, abaxial view C raceme, front view D raceme, lateral view E flowers, front view F flowers, abaxial view G1 dorsal sepal G2, 3 petals G4, 5 lateral sepals G6 labellum H anther cap, ventral view I pollinarium with pollinia. |
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| Habitat and habit of Gastrochilus balangshanensis in situ A habitat B–D flowering plants of G. balangshanensis growing on tree trunks or branches E, F fruiting plants of G. balangshanensis. Photograph credits: A–E Yue-Hong Cheng F Jun-Yi Zhang. |
Gastrochilus balangshanensis Jun Y.Zhang, B.Xu & Yue H.Cheng, sp. nov.
Diagnosis: Gastrochilus balangshanensis is most similar to G. affinis, but can be distinguished by its shorter stem (1.5–3.5 vs. 3.0–12.0 cm), nearly elliptic leaves (vs. oblong-lanceolate to subspathulate), larger sepals (5.6–6.4 × 4.8–5.2 vs. 3.0–5.0 × 1.0–1.3 mm) and petals (5.0–5.8 × 4.0–4.4 vs. 3.0–4.0 × 1.0–1.3 mm), reniform epichile (vs. subtriangular) and sub-hemispherical hypochile, obtuse-rounded at the apex (vs. hypochile obconical, subacute to obtuse and shortly bifid at apex).
Etymology: Its specific epithet refers to the Balang Mountain, type locality of this new orchid. A Chinese name, “ba lang shan peng ju lan” (巴朗山盆距兰), is suggested here.
Jun-Yi Zhang, Yue-Hong Cheng, Min Liao, Sen-Long Jin, Hong-Qiang Lin, Pan-Yan Yang, Hai He and Bo Xu. 2024. Gastrochilus balangshanensis (Orchidaceae, Aeridinae), A New subalpine epiphytic Orchid from the Mountains of Southwest China. PhytoKeys. 247: 123-135. DOI: doi.org/10.3897/phytokeys.247.130755
