Wallich's numbers are assigned to species, not to collections. This means that collections from different sites and dates may have the same number. Wallich 6663A and 6663B were collected in India (prov. Dindygul) in 1832 whereas 6663 was collected in Nepal in 1821. Both 6663A and 6663B are mentioned in the protologue and have to be considered as syntypes of Peperomia dindygulensis. Michel Gilbert and Nianhe Xia designated the K specimen of 6663B as the lectotype (Novon 9(2): 190, 1999)