Research Article |
Corresponding author: Yao-Hua Tian ( tyhyhf@126.com ) Corresponding author: Yun-Hong Tan ( tyh@xtbg.org.cn ) Academic editor: Eberhard Fischer
© 2022 Yan-Xiong Gong, Hong-Bo Ding, Xiang-Shuai Yan, Fang Wen, Yao-Hua Tian, Yun-Hong Tan.
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:
Gong Y-X, Ding H-B, Yan X-S, Wen F, Tian Y-H, Tan Y-H (2022) Oreocharis polyneura, a new species of Gesneriaceae from southern Yunnan, China. PhytoKeys 214: 7-15. https://doi.org/10.3897/phytokeys.214.93901
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Oreocharis polyneura, a new species from southern Yunnan, China, is described and illustrated. It is morphologically similar to O. rhytidophylla by having more obvious lateral veins forming a crosslinked network on the adaxial surface of leaf blades, but can be distinguished by having more lateral veins (12–15 pairs vs. 7–9 pairs) of leaf blades, shorter corolla tubes (the length ratio of corolla tube to corolla lobes = 1.2–2.9 vs. 3.4–6) and shorter pistils (6–8 mm long vs. 27–30 mm long). In addition, a detailed morphological description, a photographic illustration, the distribution and phenology of the new species are presented.
flora of Yunnan, morphology, new taxon, Oreocharis rhytidophylla, taxonomy
In recent years, the genus Oreocharis Benth. has been a hotspot for the research of the family Gesneriaceae. The newly circumscribed genus Oreocharis is recently enlarged by incorporating ten other genera (Ancylostemon Craib, Bournea Oliv., Dayaoshania W.T.Wang, Deinocheilos W.T.Wang, Isometrum Craib, Opithandra B.L.Burtt, Paraisometrum W.T.Wang, Thamnocharis W.T.Wang, Tremacron Craib, Briggsia Craib s.str.) with high floral diversity (
In 2021, during the expedition of the plant resources of tropical Yunnan in China, we collected an interesting plant of Gesneriaceae from Lancang county at anthesis (Figs
Oreocharis polyneura Y.H.Tan, F.Wen & Y.X.Gong, sp. nov. A habit B inflorescence C behind view of flower D fruit E whole plant F inflorescence with scale G adaxial and abaxial leaf surfaces H bracts I, J calyces K opened corolla showing stamens and staminode L pistil with disc and calyces M cross section of fruit. Photographed by Yan-Xiong Gong.
Vouchers of the new species were collected from Lancang County, Yunnan Province, China. Photographs and phenology data were obtained during field expeditions. Morphological examinations and measurements of the new species were conducted on both living plants in the wild and herbarium specimens. All morphological characters are described according to the terminology presented by
Oreocharis polyneura is similar to O. rhytidophylla in having more obvious lateral veins forming crosslinked network on the adaxial surface of leaf blades, but can be distinguished by having more lateral veins (12–15 pairs vs. 7–9 pairs) of leaf blades, shorter corolla tubes (the length ratio of corolla tube to corolla lobes = 1.2–2.9 vs. 3.4–6) and shorter pistils (6–8 mm long vs. 27–30 mm long).
China. Yunnan Province, Puer City, Lancang County, Zhutang Town, on rocks or cliffs in evergreen broad-leaved forests in ravines, 22°45'44.28"N, 99°43'26.81"E, elev. 2137 m, 29 July 2021, Y.X. Gong G344 (holotype: HITBC0079099; isotypes: HITBC, IBK). Fig.
Perennial herbs. Rhizomes subterete, short, straight, with numerous fibrous roots. Leaves basally forming a rosette, 4–8, petiolate; petioles terete, 1.2–7.0 cm long, 3–5 mm in diameter, densely rust-brown pannose, leaf blade thickly chartaceous, elliptic to ovate-elliptic, 4–13 × 2–7 cm, apex rounded, base rounded to subcordate, margin serrate to crenate, adaxially green, glabrous, abaxially whitish-green, densely rust-brown pannose along veins, lateral veins 12–15 on each side of the midrib, adaxially conspicuously sunken, abaxially conspicuously prominent, anastomosed forming on both surfaces. Inflorescences cymose, axillary, 2–4, 2–4-branched, 4–10-flowered; peduncles 4.5–9.0 cm long, ca. 1–3 mm in diameter, rust-brown lanate; bracts 3, verticillate, each 8.5–9.5 × 3.2–4.2 mm, lanceolate to elliptic, margins usually entire, occasionally 2–3-denticulate, adaxially glabrous, abaxially rust-brown pannose; pedicels 1.0–3.5 cm long, ca. 1 mm in diameter, sparsely puberulent. Calyces actinomorphic, 5-parted from the base, segments equal, linear-lanceolate, 7.5–9.0 × 1.5–2.5 mm, margin dentate, adaxially glabrous, abaxially rust-brown pannose. Corollas yellow, 1.8–2.2 cm long, outside glabrous, inside sparsely glandular-puberulent in the throat on adaxial lobes; tube narrowly infundibuliform, slightly bent near the throat, 1–1.5 cm long, 4–5.5 mm in diameter, proximally and distally almost equal in width; limb indistinctively bilabiate, adaxial lip 2-lobed, lobes obovate to elliptic, 5.8–6.2 × 3.8–4.8 mm, apex obtuse, margin entire, abaxial lip 3-lobed, lobes obovate to elliptic, almost equal, 6.2–8.2 × 5.2–6.2 mm, apex rounded, margin entire. Stamens 4, included, two pairs of stamens cohering at the anther tips, adnate to corolla tube 4–6 mm from base; adaxial stamens 3.5–4.5 mm long, abaxial stamens 5–6 mm long; filaments yellow, linear, glabrous; anthers basifixed, reniform, 2-locular, dehiscing transversely; staminode 1, 1.4 mm long, adnate to corolla tube 1.8 mm from the base. Pistils 6–8 mm long, glabrous; ovary 5–6.5 mm long, ca. 1.5 mm in diameter, glabrous, with two parietal placentae; style 1–1.5 mm long; stigma 1, disciform, retuse, edge flipped outwardly, 1.5–2.0 mm in diameter. Discs ring-shaped, ca. 2.3 mm high, margin slightly undulate with 5 irregularly and shallow lobes. Capsules indistinctively 4-angled to subterete, ca. 4 cm long, ca. 3 mm in diameter, glabrous.
Flowering from July to October; fruiting from September to November.
Greek polys, many, and neuron, nerve, alluding to abaxially conspicuous lateral leaf veins
Oreocharis polyneura is currently known only from its type locality. Based on our present knowledge and available data, its conservation status is assessed as “Data Deficient” (DD;
The Chinese name of the new species is “Duō Mài Mǎ Líng Jù Tái” (多脉马铃苣苔). The first two words, Duō Mài mean the numerous veins of the leaf blades, and the rest four words mean the genus Oreocharis in mandarin.
Morphologically, Oreocharis polyneura is most similar to O. rhytidophylla in its leaves and inflorescences but is readily distinguishable by an array of characters (see Table
Morphological comparison between Oreocharis polyneura and O. rhytidophylla.
Character | Oreocharis polyneura | Oreocharis rhytidophylla |
---|---|---|
Petiole | terete | plane |
Leaf | lateral veins 12–15 pairs | lateral veins 7–9 pairs |
Peduncle | 4.5–9 cm long | up to 14 cm long |
Corolla | 1.8–2.2 cm long; tube narrowly infundibuliform | 3.5–3.7 cm long; tube cylindric |
Length ratio of corolla tube to corolla lobes | 1.2–2.9 | 3.4–6 |
Stamen | two pairs cohered at the anther tips, adnate to corolla tube 4–6 mm from base | adaxial stamens cohered in pair, abaxial stamens free, adnate to corolla tube 8–9 mm from base |
Pistil | 6.0–8.0 mm long; ovary 5.0–6.5 mm long | 27–30 mm long; ovary 17–18 mm long |
We are grateful to Dr. Eberhard Fischer and Dr. You-Pai Zeng for their valuble comments on the manuscript. We thank Shi-Wei Guo and Jian-Wu Li for providing scanned images of specimens. We also thank Bing-Fan Yang, Guo-Yun Chen and Yi-Gang Wei for their kind help in the fieldwork. This work was financially supported by Funds of Sci-Tech Innovation System Construction for Tropical crops Yunnan Province (RF2021-3), Xishuangbanna Rubber Ecosystem Research Station of Yunnan Province (202205AM070004), National Natural Science Foundation of China (31970223), the Project of the Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences (Y4ZK111B01), the Key Sci. & Tech. Research and Development Project of Guangxi (Guike AD20159091 & ZY21195050) and the capacity-building project of SBR of CAS (KFJ-BRP-017-68).