Botanical illustration is the art of depicting the form, color, and details of plant species, frequently in watercolor paintings. They must be scientifically accurate but often also have an artistic component and may be printed with a botanical description in book, magazines, and other media or sold as a work of art. Often composed in consultation with a scientific author, their creation requires an understanding of plant morphology and access to specimens and references.
Early herbals and pharmacopoeia of many cultures have included the depiction of plants. This was intended to assist identification of a species, usually with some medicinal purpose. The earliest surviving illustrated botanical work is the Codex vindobonensis. It is a copy of Dioscorides's De Materia Medica, and was made in the year 512 for Juliana Anicia, daughter of the former Western Roman Emperor Olybrius. The problem of accurately describing plants between regions and languages, before the introduction of taxonomy, were potentially hazardous to medicinal preparations. The low quality of printing of early works sometimes presents difficulties in identifying the species depicted.
When systems of botanical nomenclature began to be published, the need for a drawing or painting became optional. However, it was at this time that the profession of botanical illustrator began to emerge. The eighteenth century saw many advances in the printing processes, and the illustrations became more accurate in colour and detail. The increasing interest of amateur botanists, gardeners, and natural historians provided a market for botanical publications; the illustrations increased the appeal and accessibility of these to the general reader. The field guides, Floras, catalogues and magazines produced since this time have continued to include illustrations. The development of photographic plates has not made illustration obsolete, despite the improvements in reproducing photographs in printed materials. A botanical illustrator is able to create a compromise of accuracy, an idealized image from several specimens, and the inclusion of the face and reverse of the features such as leaves. Additionally, details of sections can be given at a magnified scale and included around the margins around the image.