New species of Resedaceae found in Dehong, Yunnan

Stixis yingjiangensis. Credit: SHEN Jianyong

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Resedaceae is a family of mainly Mediterranean herbs. The genus Stixis is one of the six genera in the family Resedaceae. To date, China has recorded three species and one subspecies of the genus Stixis, and all these species were reported in Yunnan province.

When surveying extremely small populations of plants in southwest Yunnan, researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences and Yunnan Tongbiguan provincial Nature Reserve collected an unknown species in Dehong. After careful morphological study and literature review, they confirmed the species was new to science.

The new species was named Stixis yingjiangensis, referring to the type locality, Yingjiang County, Dehong Dai and Jingpo Autonomous Prefecture, Yunnan, China. It was published in Taiwania.

Stixis yingjiangensis is morphologically similar to S. philippinensis and S. villiflora, but differs from the two species by both surfaces with sparsely strigillose on lateral nerves, midrib and pustules, inflorescences axillary, filaments lower third pubescent, upper two thirds glabrous, ovary glabrous, etc.

Currently, only two populations have been found in Yingjiang County, the first population (eight individuals were observed) is in Nabang Town, which climbs trees at the edge of the forest. The second population (only two individuals were observed) is in Kachang Town, which grows by the roadside.

Since the species is found on the border between China and Myanmar, and the investigation in China has not been thorough enough to fully understand the natural distribution of the species. The researchers proposed the conservation status of Stixis yingjiangensis as Data Deficient (DD) according to the Red List criteria of the International Union for Conservation of Nature.

Journal Information: Jian-Yong Shen et al, Stixis yingjiangensis, a new species of Resedaceae from Yunnan, China, Taiwania (2021). DOI: 10.6165/tai.2021.66.326