# Morphological Distinctiveness and Phylogenetic Analysis of Strobilanthes malvifolia (Acanthaceae), a New Species From Dry‐Hot Valley in Yunnan, Southwest China

## TL;DR

A new plant species, Strobilanthes malvifolia, was discovered in a dry-hot valley in Yunnan, China, and is classified as endangered due to its limited range and small population.

## Contribution

The discovery and description of a new Strobilanthes species with distinct morphology and phylogenetic placement in the Chamiponella group.

## Key findings

- Strobilanthes malvifolia is a new species with cordate leaves and long petioles found in the Jinsha River Basin.
- Phylogenetic analysis places it as sister to S. japonica within the Chamiponella group.
- The species is classified as Endangered (EN) due to its restricted distribution and small population.

## Abstract

The genus Strobilanthes (Acanthaceae) is known for its high morphological diversity and taxonomically challenging. During field investigations in Yunnan, southwest China, we discovered a remarkable new species, Strobilanthes malvifolia Huan C. Wang & Huai Yu Chen, which is described and illustrated here. This species exhibits distinct morphological characteristics, including cordate leaves with relatively long petioles (up to 8.7 cm long), sparsely and irregularly rounded serrations along the leaf margin. The complete chloroplast genome of this new species was also sequenced, assembled, and annotated. It is endemic to the Jinsha River Basin in western Yunnan, and was discovered in the dry‐hot valley characterized by extreme aridity and high temperatures. Phylogenetic analyses based on nrITS sequences support its placement as sister to
S. japonica
within the Chamiponella group. Palynological examination reveals spherical, tricolporate pollen with verrucate exine sculpturing arranged in rows, consistent with the pollen type found in Chamiponella group. The species has a very restricted distribution and a small population, with no protection in any nature reserve. According to the IUCN Red List Categories and Criteria, the conservation status of this new species has been preliminarily assessed as Endangered (EN).

This article describes a new species Strobilanthes malvifolia (Acanthaceae), endemic to the dry‐hot valleys of the Jinsha River basin in Yunnan, southwest China, highlighting its distinctive cordate leaves with long petioles and irregularly crenate margins. Phylogenetic analyses based on nrITS and plastid trnL‐trnF regions, along with palynological evidence, place it as a sister species to
S. japonica
within the Chamiponella group, and it is proposed to be preliminarily classified as Endangered (EN) following the IUCN Red List criteria due to its extremely restricted distribution and small population size.