Research Article |
Corresponding author: Fang Wen ( wenfang760608@139.com ) Corresponding author: Xin Hong ( hongxin@ahu.edu.cn ) Academic editor: Yu Shui
© 2020 Zheng-Long Li, Wei-Hua Qin, Fang Wen, De-Ming He, Xin Hong.
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:
Li Z-L, Qin W-H, Wen F, He D-M, Hong X (2020) Petrocodon wenshanensis, a new species of Gesneriaceae from southwestern China. In: Shui Y-M, Chen W-H, Ren M-X, Wen F, Hong X, Qiu Z-J, Wei Y-G, Kang M (Eds) Taxonomy of Gesneriaceae in China and Vietnam. PhytoKeys 157: 183-189. https://doi.org/10.3897/phytokeys.157.39624
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A new species of Petrocodon, P. wenshanensis from Yunnan province of southwestern China, is described and illustrated here. P. wenshanensis morphologically closely resembles P. jingxiensis and P. lithophilus, but differs in vegetative and generative characters. Differences between the new species and others Petrocodon species occurring in Yunnan Province are also shown in the identification key.
Didymocarpoideae, limestone flora, new taxa, Yunnan Province
Petrocodon Hance has recently been much expanded and is now one of the most morphologically variable genera in Asian Gesneriaceae (
During an expedition to prepare a National forest resources inventory in April 2016, one of the authors, De-Ming He discovered some plants without flowers in Funing County, Wenshan Zhuang and Miao Autonomous Prefecture, Yunnan Province, south-western China. Afterwards, the other authors collected specimens from the same cave when they were undertaking the field works in ecologically functional zones of Yunnan Province. On the basis of its habit (leaves in basal rosette), corolla shape (limb 2-lipped), number of fertile stamens (two), anthers (dorsifixed, coherent apically) and capsule dehiscence (loculicidal), it was identified as belonging to Petrocodon s.l. (
Diagnostic character differences between Petrocodon wenshanensis and its close relatives: P. jingxiensis, P. lithophilus.
Character | P. wenshanensis | P. lithophilus | P. jingxiensis |
---|---|---|---|
Leaf blade | apex acute | apex rounded | apex obtuse or rounded |
Bracts | glabrous inside | pubescent on both sides | pubescent on both sides |
Calyx | glabrous inside | pubescent inside | puberulent inside |
Corolla | purple | light greenish yellow | purple |
Corolla tube | gradually dilated and bent towards the throat | thin tubular | slender |
Corolla lobes | apex acute, margin erosulate near the apex | apex acute, margin entire | apex round, margin entire |
Filaments | strongly geniculate at the middle, glabrous | straight, glabrous | straight, puberulent |
1 | Adaxial corolla lip 4-fided, the abaxial integrate | 2 |
– | Adaxial corolla lip 2-fided, the abaxial 3-fided | 3 |
2 | Flower red; leaf blades elliptic | P. coccineus |
– | Flower greenish; leaf blade round | P. viridescens |
3 | Flowers greenish | P. lithophilus |
– | Flowers purple | 4 |
4 | bracts 3, corolla tubes curved | P. tenuitubus |
– | bracts 2, corolla tubes strict | 5 |
5 | Corolla lobes acuminate, not reflexed | P. wenshansnsis |
– | Corolla lobes caudate, reflexed | 6 |
6 | Leaf margin shallowly crenulate, apex rounded | P. hispidus |
– | Leaf margin entire, apex acute | P. ainsliifolius |
The new species is vegetatively similar to P. jingxiensis, it differs from the latter in having acute apex of leaf blade (vs. obtuse or rounded), bracts and calyx glabrous inside (vs. pubescent), corolla tubes gradually dilated and bent towards the throat (vs. slender tubular), and lobes margin erosulate (vs. entire), filaments strongly geniculate at the middle, glabrous (vs. straight, puberulent). And it is also morphologically similar to P. lithophilus, but differs by its apex of leaf blade acute (vs. rounded), bracts and calyx glabrous inside (vs. pubescent), corolla purple (vs. light greenish yellow), tubes gradually dilated and bent towards the throat (vs. thin tubular) and lobes margin erosulate (vs. entire), filaments strongly geniculate at the middle (vs. straight).
Petrocodon wenshanensis Xin Hong, W.H. Qin & D.M. He. A Habitat B habit when in flower C lateral view of corolla (arrow indicates the bent of the throat) D leaf blade E opened corolla (arrow indicates margin of corolla lobes erosulate near the apex) F stamens G pistil without corolla, showing calyx segments, inside glabrous (above), outside strigose (below) H stamens.
China. Guangxi Province, cultivated in the nursery of Gesneriad Conservation Center of China (GCCC), introduced from Yunnan Province: Muyang Town, Funing County, Wenshan Zhuang and Miao Autonomous Prefecture, 23°33'N, 105°28'E, 1,360 m a.s.l., growing in rocky crevices at the mouth of a karst cave. 14 June 2019, flowering, WF170807-06 (holotype: IBK; isotype: AHU).
Perennial herbs. Rhizomatous stem subterete, 30–75 mm long, 6–10 mm in diameter. Leaves basal, opposite and congested at rhizome apex; petiole 1.5–4.5 cm long, densely pubescent. Leaf blade chartaceous, ovate, 3–6 × 2–4 cm, apex acute, base broadly cuneiform or shallowly cordate, slightly oblique, margin crenulate, densely pubescent on both surfaces, lateral veins ca. 4 pairs on each side of midrib, concave adaxially, prominent abaxially. Cymes 1–3, axillary, 1–2-branched, 1–3(–6)-flowered; peduncles 4–6 cm long, densely glandular puberulent and sparsely strigillose; bracts 2, opposite, linear, ca. 5 × 0.8 mm, outside densely strigose, inside glabrous. Pedicels 2–8 mm long, glandular and eglandular pubescent. Calyx 5-lobed from base, segments narrowly lanceolate-linear, equal, ca. 5 × 0.9 mm, outside strigose, inside glabrous. Corolla zygomorphic, purple, 2.5–3.0 cm long, glandular and eglandular pubescent on both sides; corolla tubes infundibula-form, slender, gradually dilated and bent towards the throat; 17–19 mm long, 4–6 mm in diameter at the mouth, 2–2.5 mm in diameter at the base; limb distinctly 2-lipped; adaxial lip 2-lobed to the base, lobes ca. 8 mm long, orbicular triangular, apex acute, margin erosulate only near the apex; abaxial lip 3-lobed to the base, lobes 8–9 mm long, subequal, oblong, apex acute, margin erosulate only near the apex to nearly entire. Stamens 2, adnate ca. 10 mm above the corolla base, glabrous; filaments 2–3.5 mm long, strongly geniculate at the middle; anthers yellow, nearly reniform, ca. 1 mm, fused by their entire adaxial surfaces, dehiscing longitudinally; staminodes 3, linear, 0.5–0.7 mm long, adnate ca. 8 mm above the corolla base. Disc ring-like, ca. 0.7 mm high, with repand margin. Pistil 1.3–1.5 cm long; ovary ca. 2 × 1 mm, pilose; style 11–13 mm long, densely pilose, stigmas 2, ovate, ca. 0.6 mm long, lobes ca. 0.4 mm long. Capsule narrowly elliptic, dehiscing loculicidally into 2 valves.
The specific epithet is derived from the type locality, Wenshan Zhuang and Miao Autonomous Prefecture, Yunnan Province, China.
Wén Shān Shí Shān Jù Tái (Chinese pronunciation); 文山石山苣苔 (Chinese name).
The new species has so far been found only in the type locality, Muyang Town, Funing County, Wenshan Zhuang and Miao Autonomous Prefecture, Yunnan Province, China. The geographical distributions of Petrocodon wenshanensis and its similar species are identified in Figure
The landform of the type locality is karst topography, and the new species seems locally abundant in the limestone cave, the type locality. But all individuals grow on moist and shaded rocky faces on the cliff at the mouth of a karst cave. After carefully estimating and counting, the type population consists of approx. 8000 mature individuals. Although this type of cave is near the Wenshan Nature Reserve, it is also very close to the local village, so is excluded from the range of the reserve and is not protected by the reserve’s law. Hence it is easily disturbed by human activities (i.e reclamation and quarrying activities). Based on five careful field investigations over recent years, there has been no significant change in the number of individuals Thus, following the IUCN Red List Categories and Criteria (
This study was financially supported by the National Natural Science Foundation of China (31860047), the Anhui Provincial Natural Science Foundation (1908085QC1), Key University Science Research Project of Anhui Province (No. KJ2017A022), Anhui University Doctor Startup Fund, EMREF Scholarship Award of The Gesneriad Society, Anhui University Doctor Startup Fund, Key University Science Research Project of Anhui Province (No. KJ2017A022), Fund of Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain (No. 19-050-6) and Science Research Foundation of Guangxi Academy of Sciences (2017YJJ23022).