Collecting plant specimens and making herbarium specimens was quintessential for an 18th century botanist. If we want to know more about how botanists in the early 18th century approached the science of botany we need to study the plant specimens themselves.Several dried plant specimens in a large 18 th century herbarium kept at Naturalis, Leiden, have at one time been identified as originating from Herman Boerhaave (1668-1738). These specimens have now been studied extensively and their origin established.We updated the existing identifications of the plant specimens and studied the way the specimens were mounted, the handwritings on the various labels and the use of decorations.The aim of this study was to establish which specimens came from Boerhaave and why relative few of them survived.We established which specimens were 'true' Boerhaave specimens. We completed the identification of most specimens and linked the extant labels to the seed register of the Leiden Hortus botanicus. The transcription of the text on the labels labels provided us with valuable information about the introduction and cultivation of indigenous and exotic, predominantly Mediterranean, plant species.Little effort has been put into connecting the contribution by Boerhaave with the output of the living collection of the Leiden Hortus botanicus at the time, that is, the herbarium specimens we now know to have been named by Boerhaave. By studying these specimens in their entirety we made his contribution visible.