De Materia Medica Novae Hispaniae Philippi Secundi Hispaniarum ac Indiarum Regis Invictissimi Iussu is a monumental work by Francisco Hernández, commissioned by King Philip II of Spain. Between 1570 and 1577, Hernández embarked on an extensive expedition to New Spain (modern-day Mexico), tasked with documenting the natural history, flora, fauna, and indigenous practices of the region. The result was a comprehensive manuscript that detailed over 3,000 plant species, approximately 500 animal species, and various minerals, accompanied by more than 2,000 illustrations. This endeavor was not merely botanical but encompassed a holistic view of the New World’s natural and cultural tapestry.

The manuscript, written in Latin, was transcribed by Nardo Antonio Recchi, the royal protomedicus of Naples, who dedicated the work to King Philip II. It was presented as a codex, likely produced at El Escorial, Madrid, between 1577 and 1587. The work is divided into several books, covering topics such as aromatics, medicinal plants, and indigenous substances like tobacco. Notably, many of the plants are identified by their Nahuatl names, reflecting Hernández’s commitment to preserving indigenous knowledge. The manuscript also includes an index of medicinal substances, showcasing its practical utility for medical practitioners of the time.

Despite its significance, much of Hernández’s original work was lost in a fire at El Escorial in 1671. However, the surviving manuscripts have been preserved and studied over the centuries, offering invaluable insights into the early interactions between European and indigenous medical knowledge. The work stands as a testament to the meticulous scholarship and cultural exchange of the 16th century, bridging the Old and New Worlds through the lens of natural history and medicine.