By Amy Weiss

Mar 6 2019

When a researcher names a new species of algae, fungi, or plant, in addition to a published description of the species, they must also designate one specimen to serve as a reference for the new name.  

This specimen is the type, and serves to anchor a particular name. A specimen is worth a thousands words, especially when future botanists are trying to apply the name: they can visually check key characteristics, better understand what the botanist who described the name meant if written descriptions are unclear or lacking, and compare the type specimens of different species before deciding to describe a new one. 

The current rules (yes, there are rules) specify that a single specimen at a particular herbarium must be selected as the type — it is called the holotype. Any duplicates of that specimen (with the same collector, collection number, and date) are called isotypes. There are other types of types, but those are stories for another day.

Given their importance, type specimens are often specially curated in herbaria. At the New York Botanical Garden types are filed separately. This makes them easier to find, reduces wear, and in cases of emergency makes it easier to keep them safe.