There are now a total of 12 species of Wrightia known from Thailand, one of which,
W. antidysenterica (L.) R.Br., is only known from cultivation. Wrightia sp. 1 in Middleton
(1999) has since been described as Wrightia sirikitiae (Middleton & Santisuk, 2001). Two
subspecies within Wrightia pubescens were recognised by Middleton (2005). The
subspecies found in Thailand is Wrightia pubescens subsp. lanitii (Blanco) Ngan. A
completely revised key to the species is here presented