Fenghwaia, a new monotypic genus of Rhamnaceae from China

Field investigation made the taxonomic researchers from South China Botanical Garden of Chinese Academy of Sciences find the new species Fenghwaia gardeniicarpa, belonging to the monotypic genus Fenghwaia of the family Rhamnaceae.

The new species Fenghwaia gardeniicarpa is a treelet and grows in the seaside mountains of Jiangmen City, Guangdong Province, China. It caught our eyes firstly by its cylindrical and longitudinally ribbed drupaceous fruits, looking like Gardenia jasminoides, but its alternate and anisophyllous leaves implied that it was probably a member of the family Rhamnaceae.

From 2019 to 2020, several field expeditions to observe and collect its tiny and inconspicuous flowers indicated that the plant was surely closed to Rhamnus and Sageretia by having 5 cucullate flower petals and 3-clcular ovary, etc. However, the characters of its inferior ovary and dorsiventrally compressed seeds with elongated basal appendage are much different from those of all other genera.

Further analysis to its morphological and palynological characters, as well as the phylogenetic analysis based on nuclear ribosomal internal transcribed spacer (ITS) and plastid trnL-F intron spacer (trnL-F), revealed that this species is a new species and represents a monotypic genus of the family.

A global conservation assessment according to the guideline of International Union for Conservation of Nature Red List categories and criteria is performed and classifies Fenghwaia gardeniicarpa as Near Threatened (NT), because the plants are well protected in a nature reserve and the population is not severely fragmented and no population decline and no extreme fluctuations caused by natural events have been observed in their habitats.

This new genus Fenghwaia is one of the 17 monotypic genera of the family Rhamnaceae. The founding of Fenghwaia gardeniicarpa provided important material to elucidate the evolution of the genus and the phylogeny and biogeography of the family.

The generic name is dedicated to Professor CHEN Fenghwai (1900-1993), a Chinese plant taxonomist who contributed a lot to the botanical gardens in China.

For further reading, please refer to: https://doi.org/10.3897/phytokeys.171.57277.