Based on morphological observations of the type and other specimens, Lasianthus idukkianus E.S.S.Kumar & P.E.Roy, Hedyotis indirae K.M.P.Kumar & Aiswarya, and H. kottangathattiensis M.B.Viswan. & Manik. are treated as synonyms of Canthiumera neilgherrensis (Wight) K.M.Wong, Hedyotis hirsutissima Bedd., and H. purpurascens Hook.f., respectively.