Steere Herbarium, New York Botanical Garden

The William and Lynda Steere Herbarium at the New York Botanical Garden is one of the largest herbaria in the world. The whole holds more than seven million preserved specimens, including rich collections of fungi and lichens. Documentation of the Americas is particularly strong. Specimens tie an organism's name to a place and a time, so that a modern distribution map has a material foundation and not merely a point in a database.

Digitisation has changed how the collection is used. An image of a specimen, its label and catalogue data can be available without a trip to the Bronx, which makes it easier to select material for further study. Not every character can be read from a photograph, however. Microscopic structure, lichen chemistry, spore structure or verification of an old identification may require work with the original and a curator's knowledge.

A research visit requires prior approval. The herbarium asks for notice well in advance, a statement of purpose, the taxonomic group and the material. That preparation allows staff to locate collections, assess restrictions and plan a workspace. The collection's hours are not the same as the public opening hours of the botanical garden; a ticket to NYBG does not automatically give access to the research stores.

For a non-scientific audience, the significance of the Steere Herbarium is clearest in open data. You can trace historic expeditions, compare labels and see where knowledge of a species' range comes from. Errors and gaps have to be kept in mind: old names need updating, coordinates are sometimes approximate, and a large number of records from one region may indicate intensity of collecting rather than greater diversity. A herbarium is a tool for asking better questions, not a ready-made map of nature free of uncertainty. When citing a record, keep the catalogue number and the date of access, because the interpretation of a name may later be corrected without the physical specimen disappearing.

A collection made of identifiable archives

The mycological holdings of the William and Lynda Steere Herbarium contain about 600,000 specimens. Their importance is clearer in collections with traceable provenance: J.B. Ellis contributed about 100,000 specimens and 4,000 types, William A. Murrill about 70,000, and Kent P. Dumont roughly 25,000. Such archives let researchers reconstruct naming history, expeditions and distribution change, but a specimen total is not a species count. The Virtual Herbarium can expose a catalogue record and image when digitised. Consulting physical material is a research activity arranged with staff; ordinary garden admission does not automatically open the herbarium cabinets.