Clifford's Herbarium consists of 3,461 sheets upon which are mounted dried plant specimens. It is probable that George Clifford established the herbarium in the Hartekamp in the 1720s, building it up with plants not only from his own garden but also from others, and from collectors around the world. There are few direct indications of the source of any given sheet, as was common in this period. However, the origins of some of the sheets can sometimes be deduced, for instance, from clues from handwriting, the style of labels, watermarks of the mounting paper etc. (see Wijnands & Heniger, 1991).
The plants in the collection are mounted on single unconnected sheets - the method used in modern herbaria, but in contrast with the earlier practice of binding sheets in large book-like volumes such as are found in the Hans Sloane and Paul Hermann herbaria. Rather charmingly, many of the specimens are mounted such that they appear to be growing out of highly decorative, engraved paper urns, and are held down by paper ribbons and their names inscribed on ornate labels. These are peculiar to Dutch herbarium collections of the 1730s, and can be seen in Adriaan van Royen's herbarium, now at the Riksherbarium, Leiden. An account of the different urns, handwritings and watermarks found in the herbarium is provided by Wijnands & Heniger (1991) - see Bibliography.
After Clifford's death and the sale of his estate, the herbarium was bought in 1791 by Sir Joseph Banks (1743-1820), the noted natural historian, and shipped to Britain where it joined his already large collections at his house in Soho Square, London. Banks's will provided for his herbarium (including Clifford's material) to go to his librarian and assistant, Robert Brown (1773-1858), and on Brown's death to the British Museum. Brown chose to give the collection to the Museum before his death and Clifford's herbarium was initially kept as a separate part of the collections of the new Botany Department, which Brown supervised. Later in the nineteenth century, Clifford's specimens were dispersed by incorporating them in the main collection, but they were separated out again early in the twentieth century.
Clifford's herbarium is currently housed in its own cabinets, separate from the main herbaria in what is now The Natural History Museum in London. It is possible that some Clifford specimens have been overlooked and are still scattered through the main collections, but we believe these can now be only very few in number.