How are the plants stored and preserved?
Mounting a Herbarium Specimen
Large Type Specimen
Fruit from the Carpological Collection
Specimens Preserved in Spirit
Once the paper work is in place and the plants have gone through quarantine they are passed to herbarium staff who undertake family 'sorts' — to decide which family each specimen belongs to. A specialist in the relevant plant family then formally identifies the specimen to species level. The specialist may be a Kew staff member or someone working at another herbarium in another country. Once the specimens are identified they are passed to a team of skilled technicians who mount the plants on hard paper or card about 42 cm by 27-30 cm (see image). In the literature you will see these mounted collections being referred to as specimens, exsiccatae or herbarium sheets.
To mount the specimens successfully the technicians follow painstaking methods that have evolved over centuries. They aim to preserve the specimen carefully whilst exposing to view all possible aspects of a plant: its flowers — with all their petals; their fruit; seeds; the hairs on both upper and lower surfaces of the leaf and so on.
Mounted, identified specimens are stored in cupboards of an appropriate size (see image). The collections are organised carefully within these cupboards.
What are ancillary collections?
Delicate plant parts such as flowers can be preserved in spirit, bulky parts of a plant such as large fruits, very large fronds (as in some palms) or other vegetative parts (as for some cacti) will simply be dried and placed in large boxes. Kew has a separate collection of fruits dried in this way — it's called the carpological collection. Kew's Jodrell Laboratory has a DNA Bank. Kew's Economic Botany collection includes a large selection of wood samples. Such collections are normally cross-referenced to herbarium dried-pressed specimens.