Researcher Chen Hongfeng and his team from the South China Botanical Garden of the Chinese Academy of Sciences have published a new species in the section Siderostictae of the Carex genus - Carex qingyuanensis, with the support of key research and development projects in Guangdong Province. The related findings were recently published in the international taxonomy journal "PhytoKeys."
"The discovery of Carex qingyuanensis enriches the distribution records of species in the Carex genus section Siderostictae in Guangdong Province," said Chen Hongfeng, the corresponding author of the paper. The sedge family Carex includes over 2,000 species, making it one of the largest genera of angiosperms, nearly ubiquitous worldwide. With the development of sequencing technologies, the internal relationships within the Carex genus have become increasingly clear. The latest research results indicate that the Carex genus comprises 6 subgenera, 62 sections, and 49 groups. Since 2010, around 40 new species of Carex have been continuously discovered in China.
In February 2022, Chen Hongfeng and his team, accompanied by Zeng Qiugan, a senior engineer at the Forestry Bureau of Qingyuan City, Guangdong Province, and Zhang Mingkai, the director of the Bijiashan Forest Farm, conducted a plant survey at the Bijiashan Forest Farm in Qingyuan City, Guangdong Province. They discovered a suspected new species of Carex during the survey, collected specimens on the spot, and introduced them back to the South China Botanical Garden for further morphological and phenological observations. Through botanical studies and consultations with researcher Deng Yunfei at the South China Botanical Garden, combined with observations of flower and fruit morphology under a stereomicroscope, they tentatively identified the species as belonging to the Carex genus section Siderostictae, with morphological similarities to the fanleaf sedge (C. peliosanthifolia) in the same group.
Furthermore, Chen Hongfeng's team visited the herbarium to examine specimens of the fanleaf sedge, comparing the differences in inflorescence branching and fruit morphology between the two species. Simultaneously, they regularly observed the growth of the introduced plants, recorded the phenological changes of the plants with a camera, and further observed and recorded the flower and fruit morphology. Researchers found significant differences between the new species and the fanleaf sedge in terms of inflorescence branching, number of spikelets, shape of the male inflorescence, enlargement of the base of the style, and beak morphology.
In July 2023, Chen Hongfeng and his team collected specimens of the fanleaf sedge and the Carex pedunculata in Jinxiu Mountain, Guangxi, and obtained fragments of two nuclear genes and three plastid genes from the new species, fanleaf sedge, and Carex pedunculata. By combining data from NCBI with five gene fragments from 21 species belonging to 2 sections and 3 clades, they constructed an ML tree with support rates exceeding 90%, showing consistent relationships between sections and clades as well as previous research results, ensuring the reliability of the results. Researchers found that the new species is more closely related to the fanleaf sedge and the Carex pedunculata compared to the fanleaf sedge, with the two species being sister groups. Therefore, molecular evidence also indicates that this species is a new species in the section Siderostictae. Based on the collection location of the holotype of the new species, it was named Carex qingyuanensis.
The section Siderostictae includes 27 species from three traditional groups: Carex pedunculata group, Carex qingyuanensis group, and Carex stenophylla group. Carex qingyuanensis belongs to the traditional Carex pedunculata group, characterized by the presence of unisexual flowers in the same inflorescence, fan-shaped leaves up to 12 cm wide, and distinctive solitary or compound conical inflorescences. Eight species have been reported in this group in China, mainly distributed in evergreen broad-leaved forests in central and southeastern China (including Taiwan). Despite the small number of species in this group, the subtle morphological differences pose significant challenges in classification.
Related paper information: https://doi.org/10.3897/phytokeys.241.117734
Comparison of the morphology of Eulalia and Miscanthus species (Figure A: Eulalia habitat; B, D: Eulalia inflorescence; C, E: Miscanthus inflorescence; F: Eulalia spikelet; G: Miscanthus spikelet; H: Eulalia fruit; I: Miscanthus fruit; J: Immature fruit and enlarged base of style in Eulalia; K: Immature fruit and non-enlarged base of style in Miscanthus). Image provided by the research team.
