# Morphological and Molecular Evidence for a New Species Within Styrax (Styracaceae) from a Karst Area in Southwest Guangxi, China

## TL;DR

A new plant species, Styrax chongzuoensis, was discovered in limestone regions of Guangxi, China, and is distinct from similar species based on leaf shape and genetic analysis.

## Contribution

The discovery and description of a new endemic plant species, supported by morphological and molecular phylogenetic evidence.

## Key findings

- Styrax chongzuoensis differs from Styrax fortunei by leaf shape and flower count.
- Phylogenetic analysis shows S. chongzuoensis is closely related to Styrax japonicus.
- The species is narrowly distributed in limestone areas of Chongzuo, Guangxi.

## Abstract

Styrax chongzuoensis, a novel endemic species with a narrow distribution in limestone regions of Chongzuo, Guangxi, China, is described herein. This new species seems somewhat similar to Styrax fortunei, but significantly differs from it by having long ovate or long lanceolate leaves, often with an asymmetrical base (vs. obovate-elliptic to elliptic, often with a symmetrical base) and fertile shoots with fewer flowers (1, or rarely 2 or 3, vs. many, always more than 10). Phylogenetic analyses based on the chloroplast coding sequences indicated that S. chongzuoensis and Styrax japonicus are sister taxa to each other, both clustered in the series Cyrta within Styrax. Overall, the integration of morphological and phylogenetic evidence indicates that S. chongzuoensis actually represents a new species. Color plates of S. chongzuoensis are illustrated, and a distribution map and conservation assessment of this species are also provided.