The typification of Rivca ornata (Roxb.) Choisy (Convolvulaceae), based on Lettsomia ornata Roxb., is discussed. R. ornata is shown to have been frequently (though not consistently) misapplied to a taxon from S India and Sri Lanka which has also been called Convolvulus candicans Roth ex Roem. & Schult., nom. illegit.; it is here newly described as R. wightiana R.R. Mill. Lettsomia ornata was based on a specimen of a plant introduced to Calcutta Botanic Garden from Uttar Pradesh. This is synonymous with Rivea ornata var. griffithii C.B. Clarke, not Clarke's ‘typical variety’ which Prain formally named var. typica. Lectotypifications are proposed for two species names in Argyreia Lour. Calystegia hederacea Wall., Convolvulus arvensis L. and Dichondra repens J.R. & G. Forst. are recorded from Bhutan for the first time.