A silent herbarium? Joseph de Jussieu’s botanical collections from South America (1735–1770)

The vast herbarium amassed by the Jussieu family in France in the eighteenth and early nineteenth centuries contains some 400 specimens attributed to Joseph de Jussieu (1704–1779) , who collected them while in the Viceroyalty of Peru between 1735 and 1770. Many of these specimens arrived in France without labels or with very laconic ones. Most of the descriptions were lost. In the 1770s–1780s, Antoine-Laurent de Jussieu (1748–1836) attempted to name the plants and complete the descriptions, by comparing Joseph’s collections with those of other travellers. In a manuscript devoted to some ‘Plantes Nouvelles du Pérou [New plants from Peru]’, Antoine-Laurent described the difficulty of transforming his uncle’s botanical material into valid knowledge. By examining this manuscript and the plants it describes, I will take the opportunity to explore this part of Joseph de Jussieu’s herbarium and the difficulties it highlights in terms of the production of botanical knowledge. Given the state of Joseph’s collections, when Antoine-Laurent de Jussieu confronted them his role was partly that of a translator as he transformed Joseph’s approximate polynomials into Linnaean binomials after analyzing each herbarium sample. A close analysis of four genera will illustrate how the natural method A.-L. de Jussieu developed while working on his uncle’s collections fed into the botanist’s thinking on natural families.