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| Hoya pyrifolia E.F. Huang in Huang, Yao, Jiang, ... et Zhang, 2021. |
Abstract
Hoya pyrifolia, a new species of Apocynaceae from Yunnan Province, China, is described and illustrated. Results from phylogenetic analyses, based on combined DNA fragments of the nuclear ribosomal external transcribed spacer (ETS), intergeneric transcribed spacer (ITS) and three plastid DNA fragments (matK, psbA-trnH and trnT-trnL), showed that the new species was nested within a clade, including Hoya species distributed in the subtropical foothills of the Himalayas and the Tibet-Sichuan Plateau. Morphologically, the new species can be distinguished from its close relatives by its pyriform and slightly pubescent leaves, as well as the 4-flowered inflorescences.
Keywords: Apocynaceae, Asclepiodoideae, China, Hoya, taxonomy
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| Figure 3. Hoya pyrifolia E.F. Huang A habit B leaf C inflorescence D bracteole E calyx lobes F corolla, adaxial side G corolla, abaxial side H corona I corona lobe J pollinarium K fruit L seed. Drawn by Y.J. Chen. |
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| Figure 4. Hoya pyrifolia E.F. Huang A habit showing inflorescences and mature follicles B branch and inflorescence C corona lobes D corona top view E flower F bracteoles G pollinarium H pedicel and calyx lobes I part of Pedicel J corona side view K leaves L seed. |
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| Inflorescences of Hoya species G H. chinghungensis (Y. Tsiang & P.T. Li) M.G. Gilbert, P.T. Li & W.D. Stevens; I H. kingdonwardii P.T. Li; J H. engleriana Hosseus; K H. lanceolata Wall. ex D. Don; L–N H. longicalyx W. Hui & E.F. Huang |
Hoya pyrifolia E.F. Huang, sp. nov.
Diagnosis: The species is morphologically most similar to H. engleriana, but differs by its leaves which are pyriform and 10–14 mm long (vs. narrowly oblong and 20–25 mm long), its 4-flowered inflorescences (vs. 5–7-flowered), its calyx lobes ca. 4 mm long (vs. 1.5–2 mm long) and the triangular corolla (vs. narrowly oblong to oblong-triangular).
Etymology: Hoya pyrifolia is named for its pyriform leaf, which is a significant feature that can be used to distinguish the species from its close relatives.
Distribution and habitat: The species is endemic to Gaoligong Mountain, distributed in Longling and Yingjiang Counties in Yunnan Province. It is an epiphyte on tree trunks in the mid-montane evergreen forests at an elevation from 1850 m to 2150 m.
Er-Feng Huang, Gang Yao, Ri-Hong Jiang, Lei-Lei Yang, Wang Xi, Zhong-Shuai Zhang and Xian-Chun Zhang. 2021. Hoya pyrifolia (Apocynaceae), A New Species from south-western Yunnan, China. PhytoKeys. 174: 95-106. DOI: 10.3897/phytokeys.174.60137
