Chrysosplenium sangzhiense (Saxifragaceae), a new species from Hunan, China.

Long-Fei Fu,De-Qing Lan,Tian-Ge Yang,Hong Liu,Fang Wen

doi:10.3897/phytokeys.176.62802

Abstract

Chrysosplenium sangzhiense Hong Liu, a new species from Hunan, China, is described and illustrated. The phylogenetic analysis revealed that the new species belongs to subgen. Chrysosplenium and is closely related to C. grayanum, C. nepalense and C. sinicum. The chromosome number of the new species is 2n = 46, indicating a novel basic number x = 23 in Chrysosplenium that is different from other species. This also suggests that C. sangzhiense is probably an allopolyploid derivative of a species with x = 11 and one with x = 12. Morphologically, C. sangzhiense can be easily distinguished from C. grayanum, C. nepalense, C. sinicum and C. cavaleriei, a species not included in our phylogenetic analysis by a suite of characters relating to the sterile shoots, basal leaves, cauline leaves, flowering stem, sepals, disc, capsule and seed. A global conservation assessment is performed, and classifies C. sangzhiense as Least Concern (LC).

Highlights

Chrysosplenium L. (1753) is a perennial herbaceous genus in Saxifragaceae and comprises more than 70 species (Kim et al 2019; Fu et al 2020)
C. sangzhiense can be distinguished from C. grayanum, C. nepalense, C. sinicum and C. cavaleriei, a species not included in our phylogenetic analysis by a suite of characters relating to the sterile shoots, basal leaves, cauline leaves, flowering stem, sepals, disc, capsule and seed
No particular infra-generic classification was adopted in this revision, use of leaf arrangement as the primary character in the key to species reflected the recognition of two subgenera in previous taxonomic revisions (Pan 1986a, b)

Summary

Introduction

Chrysosplenium L. (1753) is a perennial herbaceous genus in Saxifragaceae and comprises more than 70 species (Kim et al 2019; Fu et al 2020). Chrysosplenium is distributed in Asia, America and Europe (Pan and Ohba 2001; Soltis 2007). The latest revision of Chinese Chrysosplenium included 35 species (Pan and Ohba 2001). No particular infra-generic classification was adopted in this revision, use of leaf arrangement as the primary character in the key to species reflected the recognition of two subgenera in previous taxonomic revisions (Pan 1986a, b). Soltis et al (2001) showed that the two subgenera are both monophyletic and sister to each other using matK sequence data, thereby confirming that leaf arrangement is a phylogenetically informative morphological character. Subsequent taxonomic research on Chinese Chrysosplenium has been undertaken by Liu et al (2016), Kim et al (2019) and Fu et al (2020), bringing the total diversity of the Chinese flora to 38 species, of which 23 (60%) are endemic

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