The “Catalogue of Economic Plants in the Collection of the U.S. Department of Agriculture,” authored by William Saunders in 1891, serves as a comprehensive reference detailing various plants of economic importance housed within the U.S. Department of Agriculture’s collection. This work aims to provide insight into the diverse applications of plants, ranging from food and medicine to materials and ornamental uses. Each entry in the catalogue offers a description of the plant’s origin, uses, and significance, reflecting the agricultural and botanical knowledge of the late 19th century.​

The catalogue is organized systematically, with each plant listed alphabetically and accompanied by detailed information. For instance, Abrus precatorius, commonly known as wild liquorice, is noted for its small, scarlet seeds used in jewelry and as a standard of weight in India. The roots of this plant yield liquorice, extracted similarly to that from the true Spanish liquorice plant, Glycyrrhiza glabra. Another example is Coffea arabica, the coffee plant, native to Abyssinia but now cultivated in many tropical regions. The catalogue provides insights into the cultivation requirements and processing methods of coffee beans, highlighting their economic significance.​

In addition to detailing the uses of these plants, Saunders also emphasizes their cultivation and economic potential. For example, Colocasia esculenta, known for its edible root-stock, is recommended for profitable culture due to its starch-filled roots, which have long been used as food in various semitropical countries. The catalogue thus serves as both a botanical reference and a practical guide for agricultural development, showcasing the utility of plants in various sectors.​

Saunders’ catalogue is a valuable resource that not only catalogs the plants within the U.S. Department of Agriculture’s collection but also underscores the multifaceted roles these plants play in human society. By documenting the economic uses of plants, the work contributes to a deeper understanding of the relationship between humans and the plant kingdom, offering insights that remain relevant to agricultural and botanical studies today.