ABSTRACT
The preface contains the acknowledgements, discusses the Essai’s connection with the voyage to America, and notes the presence of Bonpland. The Essai itself does not have sub-chapters or headings.
Humboldt calls on botanists to take up, in addition to their conventional work, the study of plant geography, which he describes as a science related to “general physics” which “examines plants on the basis of their local association in various climates”.
Plant geography establishes the distribution of plants according to climate. It distinguishes species which “grow scattered and isolated” from those which are grouped in a society and cover large expanses of terrain, from which they exclude other species. These social plants are more numerous in temperate countries than in the tropics.
Plant geography is linked to the geological history of the planet, but also to the history of humanity and its migrations, which involve the movement of plants. Finally, plant geography explains “the influence that plants exert on the taste and imagination of peoples”, which requires an analysis of the character of plants. To this end, from the many diverse plant forms, Humboldt distinguished fifteen groups based exclusively on the physiognomy of plants.
