“…is one of the largest genus in the tribe Gomphostemmateae (subfamily Lamioideae, Lamiaceae; Scheen et al, 2010; Zhao et al, 2021; Bongcheewin et al, 2022) and was first formally established by Bentham (1830), having first appeared in the Wallich Catalogue (Wallich, 1829). Since then it has been studied by various authors (Bentham, 1835, 1848, 1876; Wallich, 1831; Hooker, 1880, 1885; Prain, 1890, 1891; Briquet, 1897; Ridley, 1923; Keng, 1969, 1978; Murata, 1976; Hedge, 1990; Ryding, 1994; Li & Hedge, 1994; Hsieh & Huang, 1998; Khanam et al, 2003; Harley et al, 2004; Xiang et al, 2008, Xiang et al, 2010, Xiang, Funamoto, et al, 2013, Xiang, Zhang, et al, 2013; Scheen et al, 2010; Walsingham & Bramley, 2010; Bendiksby et al, 2011; Bongcheewin, 2013; Bongcheewin et al, 2014, 2022; Li et al, 2016: Turland et al, 2018; Zhao et al, 2021). Prain (1891) published a complete monograph of the genus.…”