An accession in our collection can be represented by a single specimen or by dozens of individuals - what makes each an accession is the fact that each represents a single collection event, at a single location, on a particular date.

As an example: Seeds gathered on September 30, 2010 from a single population of Coyote Bush (Baccharis pilularis) growing on the southwest side of San Bruno Mountain in San Mateo County, California, and subsequently sown and grown at the Botanic Garden could be considered a single accession. If seeds were collected from a particular individual with especially large leaves (or other feature) at the same time, and if these were kept separate, this collection could be considered a different accession.

How one chooses to apply accession numbers depends on what one wants to track and the purpose of one's collection. At the Regional Parks Botanic Garden, our collection is used for scientific research, conservation, restoration, public education, and for our visitor's enjoyment.

The plant labels in the garden contain an accession number of the form YY.NN, where YY is the collection year and NN is the collection number, and the collection location.