Plenasium vachellii is a fern in the familyOsmundaceae.[1] The genus Plenasium is recognized in the Pteridophyte Phylogeny Group classification of 2016 (PPG I);[2] however, some sources place all Plenasium species in a more broadly defined Osmunda, treating this species as Osmunda vachellii.[3] It is native to south-central and southeast China (including Hainan) and Indochina (the Malayan peninsula, Myanmar, Thailand and Vietnam).[3]
^PPG I (2016), "A community-derived classification for extant lycophytes and ferns", Journal of Systematics and Evolution, 54 (6): 563–603, doi:10.1111/jse.12229, S2CID39980610