Marchantiaceae

Zheng, Tian-Xiong, Long, David G. & Shimamura, Masaki, 2023, Range extension of Marchantia formosana (Marchantiaceae, Marchantiophyta), with an updated key to Marchantiaceae taxa in East Asia, Phytotaxa 612 (1), pp. 93-98 : 96

Notes on Marchantiaceae taxa in East Asia

With the publication of novel and regionally recorded taxa, the Marchantiaceae in East Asia is represented by three well-recognized genera ( Zheng & Shimamura 2022a), including 14 taxa (Bischler-Causse 1989; Long & Crandall-Stotler 2020; Xiang et al. 2016, 2022; Zheng & Shimamura 2020, 2022a, 2022b; Zheng & Long, 2023). Among them, some taxa doubtfully recorded in the Chinese bryoflora ( Marchantia emarginata subsp. emarginata and M. stoloniscyphulus (Gao & Chang 1982: 114) Piippo 1990: 134 ) warrant a brief discussion in this study. Marchantia emarginata subsp. emarginata was first reported by Chao (1943, as “ M. palmata Nees ”) and subsequently recorded in some regional studies (Jia & He 2013; Xiong & Cao 2018) in China. However, Zheng (unpublished) found that (1) subgeneric classification of the M. emarginata complex is geographical rather than morphological, (2) there is excessive morphological diversity within the specimens identified as subsp. emarginata by the original author and (3) the distinguishing character of this subspecies (e.g., epidermal papillae and narrower appendages of ventral median scales) are not easily observed in some Southeast Asian specimens, indicating that the present treatments and morphological definition of subsp. emarginata are not tenable and need to be further reviewed. For M. stoloniscyphulus, Zheng et al. (unpublished) have been able to show that it is conspecific with M. papillata Raddi (1822: 20) subsp. grossibarba ( Stephani 1894b: 221) Bischler (1989: 78) rather than being an independent species. Therefore, both taxa should be excluded from the following key.