Discovery of a New Cucurbitaceae Species in Motuo, Xizang, China——Herpetospermum motuoensis

Recently, a scientific research team comprising multiple institutions such as the Plant Science Research Center of the South China Botanical Garden, Chinese Academy of Sciences, Xizang University, and Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, discovered a new species of Cucurbitaceae plant in Motuo County, Xizang. The new species has been named "Herpetospermum motuoensis Y. S. Chen & B. Y. Zhang."

‌Characteristics of the New Species‌

Herpetospermum motuoensis belongs to the genus Herpetospermum within the Cucurbitaceae family. It is a dioecious vine. This new species is closely related to Herpetospermum operculatum, sharing the characteristic of a lid-like dehiscence in mature fruits. However, it can be distinguished by its inconspicuous male flower bracts that are round to broadly oval, measuring 1-1.5 millimeters in length, nearly round to elliptical petals, 6 ovules per locule that are pendant, stigmas that are nearly round to broadly elliptical, fruits that are yellow-green, spindle-shaped to ellipsoid-spindle-shaped, glabrous, and seeds that are oblong and hexagonal with projections at each corner.

‌Discovery Process‌

In the winter of 2021, the research team received two specimens and dozens of seeds from Motuo County. After careful study and literature comparison, they preliminarily determined that these plants belonged to the genus Herpetospermum. However, the sown seeds did not germinate in 2022. It was not until October 2023 that the research team returned to Motuo County for a field investigation, successfully observing this plant in the wild and collecting specimens. Through detailed observation and comparison of its morphological characteristics, the team finally confirmed that this was an undescribed new species.

‌Distribution and Conservation‌

Herpetospermum motuoensis is currently known to be distributed only in Motuo County, Xizang, growing in shrublands and forest edges at altitudes of 1300-2500 meters. According to the research team's investigation, five populations of this new species have been found in Motuo County. One of these populations contains only 4 individuals and is located alongside the road, making it vulnerable to the impacts of road construction and land reclamation and facing the risk of disappearance.

‌Scientific Significance‌

The discovery of Herpetospermum motuoensis not only enriches the diversity of Cucurbitaceae plants in China but also provides new materials and perspectives for the taxonomic study of the genus Herpetospermum. Furthermore, the discovery of this new species is of great significance for conserving biodiversity and promoting the sustainable utilization of biological resources.

The relevant research findings were published in the international taxonomic journal Phytotaxa under the title "Herpetospermum motuoensis (Cucurbitaceae), a new species from Xizang, China." ZHANG Buyun, a research assistant at the South China Botanical Garden, Chinese Academy of Sciences, is the first author of the paper, and CHEN Yousheng, a researcher, is the corresponding author. This research was supported by the Guangdong Basic and Applied Basic Research Flagship Program. Paper Links: https://doi.org/10.11646/phytotaxa.697.3.8

Figure 1. Herpelospermum motuoensis. A. Habitat; B. Habit; C. Tendril; D. Leaves; E. Male inflorescence; F. Top view of male flower; G. Back view of male flower; H. Longitudinal section of male flower; I. Top view of female flower; J. Back view of female flower; K. Longitudinal section of female flower; L. Fruits; M. Longitudinal section of fruit; N. Cross section of fruit; O. Seeds. A-O: all photos by BuYun Zhang based on the type, B. Y. Zhang, Y D. Xu, G. F. Liu et X.R. Zheng JZ20231191 (IBSC).（Imaged by CHEN et al）