From Historic England entry:
“Entrance gates and railings to the Herbarium, Kew Green.
Refurbished steel, wrought and cast iron gates and railings with decorative panels and dogbars and with spearhead finials, set on a stone plinth. These continue without a break to enclose Hanover House, also part of the RBG site, to the east.
The Herbarium at the Royal Botanic Gardens, Kew was established in 1853 by William Hooker, first Director of the Gardens. The creation of a national collection, one of Hooker’s priorities, helped to establish Kew as a leading botanic garden, its scientific importance reflecting the growth of the British Empire and increasing global exploration; the collection contained in the herbarium is of international historical significance.
A herbarium is a collection of preserved plant and fungal specimens used as a reference to identify plants and fungi. The collection at Kew is arranged phylogenetically, that is, by evolutionary classification, with specimens filed systematically by family, genus and species, the layout of the purpose-built wings reflecting this system.
The herbarium was in 1853 initially housed in Hunter House, a later C18 house overlooking Kew Green which had been previously part of the royal estate at Kew, and intended as the king’s residence.
In 1852 William Hooker had been given access to Hunter House, for at first a limited period, and then permanently, to house the collection which was to form the basis of the herbarium and its library. As well as his own library and herbarium, Hooker secured a number of eminent collections, including those of the doctor and botanist William A Bromfield, and George Bentham, Secretary of the Horticultural Society.
The herbarium continued to expand, acquiring the highly valuable East India Company collection in 1858, and by 1860, with 1.2 million specimens, Kew surpassed all other public and private herbaria in the world…”
From: A History of the County of Surrey: Volume 3. Originally published by Victoria County History, London, 1911:
“…In 1854 George Bentham the botanist presented his collections and books to Kew, in return for which a room there was assigned to him, where he worked daily at descriptive botany. Hanover House, where Ernest Duke of Cumberland, King of Hanover, dwelt from 1830 to 1831, is now the Herbarium, and Cambridge Cottage, which used to be inhabited by Augustus Duke of Cambridge, is now the museum of British forest productions…”
“Kew Herbarium, Library, Art and Archives – design by Edward Cullinan Architects.
RIBA Award winner, 19 May 2011
The new wing to the 1853 Herbarium provides a modern storage facility for the most vulnerable pieces of the existing seven million artifact collection of plant specimens and manuscripts.
The plan is essentially that of a three story rectangular red brick storage vault, linked to the main building by a western red cedar and glass clad cylindrical three storey building which also houses the reception, library and a circular reading room. The buildings are arranged to create a new entrance courtyard to the side of the main building.
The new storage vaults are designed to keep the collection at a constant temperature of 15 degrees centigrade and use a mechanical air handling and a ground source heat pump to reduce C02 emissions. The building has a BREEAM excellent rating.”