The genus Nocardioides was originally described by Prauser (Prauser, 1976), with Nocardioides albus as the type species. Currently, the genus Nocardioides comprises 139 valid species (List of Prokaryotic Names with Standing in Nomenclature; http://www.bacterio.net/nocardioides.html). Nocardioides alcanivorans (Mitzscherling et al., 2022); Nocardioides coralli (Shi et al., 2022); Nocardioides humilatus (Lee et al., 2022); Nocardioides mangrovi (Chen et al., 2022); Nocardioides nematodiphilus (Zhang et al., 2022); Nocardioides panacis (Park et al., 2022) and Nocardioides piscis (Hyun et al., 2021) were validly published in 2022. The members of genus Nocardioides contain LL-diaminopimelic acid (LL-DAP) as the diagnostic amino acid in cell-wall peptidoglycan, MK-8(H4) as the major respiratory quinone, and diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) as the major polar lipids. The DNA G+C contents are within the ranges of 66.7%-74.9%. The species of genus Nocardioides were isolated from various environments, including biofilm (Cho et al., 2013), car air-conditioning system (Park et al., 2018), desert (Khan et al., 2017), dioxin-polluted environments (Kubota et al., 2005), faeces (Wang et al., 2018), glacier (Zhang et al., 2019), lichen (Li et al., 2007), phosphate mine (Xie et al., 2017), sand (Cho et al., 2013), seafood (Lin et al., 2015), sediment (Zhang et al., 2014), sludge (Woo et al., 2012), soil (Lu et al., 2017), water flea (Tóth et al., 2008) and plant (Chen et al., 2022). During the diversity and novelty study of endophytic actinobacterium of mangrove plant in Shankou Mangrove Nature Reserve, Guangxi Zhuang Autonomous Region, China, two strains designated as BSK12Z-3T and BSK12Z-4 were isolated from surface-sterilised branch of Bruguiera gymnorhiza. In the present study, polyphasic taxonomy was used to clarify the taxonomic status of strains BSK12Z-3T and BSK12Z-4.