The 1893 Index Kewensis (IK), maintained by the Royal Botanic Gardens, Kew, is a publication that aims to register all botanical names for seed plants at the rank of species and genera. It later came to include names of taxonomic families and ranks below that of species.
The Index is currently maintained as part of the International Plant Names Index in combination with the Gray Herbarium and Australian Plant Name indexes. This database is anticipated to complete the task of creating a complete list of plant names, although it does not determine which are accepted species names.[1]