Follow or Question? Hidden Diversity and Miscellaneous Thought on the Subspecific Classification of Marchantia emarginata Reinw. Blume Nees (Marchantiaceae Marchantiophyta) Complex

摘要

Marchantia emarginata Reinw., Blume & Nees, with nearly 30 assigned names, is considered the most taxonomically complex species in the family Marchantiaceae. Currently, this species is segregated into three subspecies, and this subspecific classification is widely accepted since its formal inception. However, due to its extensive morphological variation and ambiguous intraspecific delimitation, many bryologists struggle to accurately identify this species at a subspecific level. Through scrutiny of related literatures and morphological examination of over 200 herbarium specimens, the taxonomic history, issues, and various perspectives on this species were newly summarized. Each subspecies was found to exhibit excessive morphological diversity. Consequently, the prevalent subspecific classification of M. emarginata was partly challenged by the morphological evidence obtained in the present study. This species urgently requires taxonomic revision using an integrative approach.