Knorr’s Thesaurus rei herbariae hortensisque universalis (1780) is considered one of the most attractive of the 18th century botanicals by one of the masters of the genre. From the 17th century florilegia, which focused on the decorative value of plants, had largely taken over from the herbals of the previous century which were principally concerned with plants’ medicinal value. This crucial difference had resulted from the growing fashion in the grandest gardens of Europe for the cultivation of ornamental plants from newly discovered worlds to provide spectacular displays of specimens hitherto unknown.
By the 18th century the florilegia were developing further as scientific study demanded greater accuracy for identification purposes as taxonomy (a system of classification) was established. A gifted painter, engraver, prominent collector and art dealer, Knorr also acted as an intermediary between the collectors of cabinets of natural history and those who used the specimens for scientific purposes. Knorr drew and engraved the plates himself for the Thesaurus with Latin titles drawing on different taxonomies but largely those of Carl Linneas whose system of classification is the basis for the grouping of all organisms today. Knorr’s Thesaurus, embellished with delicate hand colouring, was a precis response to the needs of the science of his time.
