Hortus Kewensis, or a Catalogue of the Plants Cultivated in the Royal Botanic Garden at Kew by William Aiton was a 1789 catalogue of all the plant species then in cultivation at the Royal Botanic Gardens, Kew, which constituted the vast majority of plant species in cultivation in all of England. It included information on the country of origin, who introduced the plant into English cultivation, and when. It is therefore now one of the most important sources of information on history of horticulture in England.