Distinct flowering plant found on Xiangzhou islands

A one-of-its-kind flowering plant has recently been discovered in the Zhuhai Wanshan Archipelago southeast of the coastline.

Named Haihoutuotong, it is distinct from any plant ever recorded in the Chinese mainland. It has small serrated obovate leaves, a flat midvein, distinct secondary veins, and disc-shaped glands. Also, the remaining carpidiophore (woody fruit base) of its opened fruit helped experts conclude that the genus belongs to the Stillingia or "Toothleaf" subspecies.

This plant is the 12th angiosperm genus (having flowers and producing seeds within an ovary or fruit) to be unveiled in the past decade in the Chinese mainland. It brings to 3,122 the number of that genus in China.  

The plant was found by researchers from the Chinese Academy of Science's (CAS) South China Botanical Garden team. Their observations and research results were published in the scientific journal Phytotaxa in a paper titled Stillingia: A Newly Recorded Genus of Euphorbiaceae From China.

Plant grows on offshore rocks [Photo by Gao Song and Xiong Weijian/Zhuhai Daily]

The abstract states: "During the last decade, hundreds of new plant species or new species records have been added to the flora of China. Nevertheless, newly described or newly recorded plant genera are not discovered and reported very often, suggesting that botanical expedition and plant survey at the generic level may be advanced in China. As far as we know, only six and eight angiosperm genera respectively have been newly described or newly recorded from China within the last ten years."

The plant's small population of no more than 200 indicates that it exists only on the Pingzhou and Wanzhou islands located closest to open waters of the Pearl River estuary. Each uninhabited island covers a mere 1 sq km (less than half a square mile).

The discovery stems from long-term large-scale observations that began in 2013. Since then, teams from South China Botanical Garden of the CAS, and Dangan and Qi'ao islands of Xiangzhou District Zhuhai have been searching tropical islands and coastal zones for protected wild plants and native biological resources. The program is supported by the Guangdong Forestry Department, CAS, and Ministry of Science & Technology.

The island ecosystem is unique, but detailed surveys of plant biodiversity on the oceanic islands are rare, said a botanist. The new findings will be of significance for China in reconstructing a natural tropical marine island reef ecosystem. It will also encourage development of a marine ecological civilization in China, he added.

Haihoutuotong (海厚托桐)  [Photo by Gao Song and Xiong Weijian/Zhuhai Daily]