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| Veronicastrum wulingense G.W. Hu & Q.F. Wang, in Ding, Jiang, Tian, Ren, Mutie, Waswa, Hu et Wang, 2023. |
Abstract
Background: The genus Veronicastrum Heist. ex Fabr. are mainly distributed in East Asia, and only Veronicastrum virginicum (L.) Farw. is disjunctively distributed in eastern North America. The south area of China (extending to Taiwan Island) is the richest in Veronicastrum species. It is of medicinal importance in China as traditional herbs used to treat ascites diseases that caused by schistosomiasis. During field investigation of plant resources in Pingbaying National Forest Park, Southwestern Hubei, China, an unknown flowering population of Veronicastrum was discovered from thick humus layers adjacent to rocks under broad-leaved forests by walkways. They were collected and morphological characters assesed for further taxonomic treatment. Molecular analysis was also conducted to ascertain its phylogenetic position in the genus Veronicastrum.
Results: This species is similar to Veronicastrum liukiuense (Ohwi) T.Yamaz. from the Ryukyu Islands, but can be distinctly differed by its axillary inflorescences (versus terminal on short leafy branches), pedicels up to 2.5 mm (versus sessile), corollas purple to purple-red (versus white tinged with pale purple) and florescence June to July (versus September to October). Also, phylogenetic studies showed the species was an independent clade in the genus Veronicastrum based on the maximum likelihood (ML) analyses using two different matrix sequences of concatenated molecular markers. The plastid genome of this new species is also reported in this study for the first time.
Conclusion: The morphological and molecular evidences support the recognition of Veronicastrum wulingense as a new species.
Keywords: Veronicastrum wulingense, New species, Southwestern Hubei, Phylogeny, Wulingshan region
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| Veronicastrum wulingense (type locality). A–B habit; C leaf sawtooth; D individual; E leaves; F axillary inflorescence in the main axis; G inflorescences; H–I flowers; J anatomical flower; K infructescences. Photographed by S.X. Ding |
Veronicastrum wulingense G.W. Hu & Q.F. Wang sp. nov.
Diagnosis: Veronicastrum wulingense belongs to the typical Veronicastrum species of axillary inflorescences (Sect. Plagiostachys species). Morphologically, it is closely similar to V. liukiuense from the Ryukyu Islands, but can be distinctly differed by its axillary inflorescences (versus terminal on short leafy branches), pedicels up to 2.5 mm (versus sessile), corollas purple to purple-red (versus white tinged with pale purple), and florescence June to July (versus September to October) (Table 1). Also, these diagnostic characteristics of peduncles up to 7 cm, flowers clustered densely in rachis apex and steadily ca. 2–3 cm long, which are unique in the all known Veronicastrum species of axillary inflorescences.
Distribution and habitat: The new species Veronicastrum wulingense is currently known only from Sidong Gorge of Pingbaying National Forest Park in the Northcentral of Wulingshan Region, Southwestern Hubei, China—its type locality. All our collections were made from the thick humus layers adjacent to rocks under broad-leaved forests by walkways, at elevations of 1000–1400 m above sea level.
Etymology: The specific epithet ‘wulingense’ refers to Wulingshan Region, where the new species is distributed.
The Chinese name is ‘Wu Ling Fu Shui Cao (武陵腹水草)’.
Shi-Xiong Ding, Hui Jiang, Jing Tian, Jing Ren, Fredrick Munyao Mutie, Emmanuel Nyongesa Waswa, Guang-Wan Hu and Qing-Feng Wang. 2023. Veronicastrum wulingense (Plantaginaceae), A New Species from Southwestern Hubei, China. Botanical Studies. 64: 3. DOI: 10.1186/s40529-023-00367-y
