Two new species of Polyalthiopsis (Annonaceae) based on morphological characters and phylogenetic evidence, with a supplementary description of P. chinensis from China

Bin Yang; Jin-Yue Li; Rui-Jie Yang; Hong-Bo Ding; Min Deng; Chun-Fen Xiao; Yun-Juan Zuo; Yun-Hong Tan

doi:10.1016/j.pld.2022.05.001

Two new species of Polyalthiopsis (Annonaceae) based on morphological characters and phylogenetic evidence, with a supplementary description of P. chinensis from China

Plant Divers. 2022 May 25;45(2):185-198. doi: 10.1016/j.pld.2022.05.001. eCollection 2023 Mar.

Authors

Bin Yang^{1

2}, Jin-Yue Li^{1

3}, Rui-Jie Yang⁴, Hong-Bo Ding¹, Min Deng⁴, Chun-Fen Xiao⁵, Yun-Juan Zuo¹, Yun-Hong Tan¹

Affiliations

¹ Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences & Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, Yunnan, China.
² The Key Laboratory of Rare and Endangered Forest Plants of National Forestry and Grassland Administration & The Key Laboratory for Silviculture and Forest Resources Development of Yunnan Province, Yunnan Academy of Forestry and Grassland, Kunming 650201, Yunnan, China.
³ College of Life Science, University of Chinese Academy of Sciences, Huairou District, Beijing 101408, China.
⁴ School of Ecology and Environmental Science, Yunnan University, Kunming 650091, Yunnan, China.
⁵ Center for Gardening and Horticulture, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, Yunnan, China.

Abstract

Two new species of Polyalthiopsis (Annonaceae), P. nigra Y.H. Tan & Bin Yang from Guangxi and Yunnan Provinces and P. xui Y.H. Tan & Bin Yang from Yunnan Province, are described and illustrated. P. nigra is morphologically similar to P. chinensis in having narrowly elliptic-oblong, lemon to yellowish green petals, but differs by having obovoid monocarps, a higher number of leaf secondary veins, leaf blades usually widest above the middle, and a lower ratio of leaf blade length to width. P. xui is morphologically similar to P. floribunda in having axillary inflorescences, 1-3(-4) flowers, elliptic leaves, and elliptic-ovate petals, but differs in the numbers of carpels per flower and ovules per carpel. The molecular phylogenetic analysis using five plastid markers confirm that the two new species belong to the genus Polyalthiopsis and show clear interspecific divergences between P. nigra and P. xui and between them and other species in the genus. Detailed descriptions, colored photographs, and habitat and distribution data for the two new species are provided. In addition, the fruit morphology of P. chinensis is described for the first time, based on living collections. Geographical distributions and a diagnostic key for all Polyalthiopsis species are also presented.

Keywords: Annonaceae; Morphology; Polyalthia; Polyalthiopsis; Southeast Yunnan.