The American Physitian by William Hughes, first published in 1672, stands as a pioneering work in the field of American medical botany. In an era when European settlers were beginning to explore the vast medicinal potential of the New World, Hughes meticulously cataloged the indigenous flora of the English plantations in America. His treatise offers detailed descriptions of various plants, trees, shrubs, fruits, and herbs, highlighting their names, growing conditions, and most notably, their applications in diet and medicine. This compilation not only served as a practical guide for early colonial practitioners but also bridged the gap between European herbal traditions and the novel resources found in the Americas.​

A distinctive feature of Hughes’s work is its emphasis on the cacao-nut tree, a crop of significant economic and cultural importance. He provides an in-depth discourse on the cacao plant, detailing the methods of harvesting its fruit and the intricate processes involved in preparing chocolate. This inclusion underscores the growing recognition of cacao’s value beyond its culinary uses, acknowledging its potential medicinal properties and economic significance in the colonial context.​

The treatise’s structure is methodical, with entries organized to facilitate easy reference. Each plant is examined in terms of its habitat, seasonal growth patterns, and therapeutic virtues, reflecting the empirical approach of the time. Hughes’s work is a testament to the early efforts in documenting and systematizing knowledge about the natural resources of the Americas, laying the groundwork for future botanical studies and the development of pharmacopoeias.​

The American Physitian is more than just a botanical catalog; it is a historical document that captures the intersection of indigenous knowledge and European scientific inquiry. Hughes’s treatise not only provided contemporary readers with valuable information about the medicinal plants of the New World but also contributed to the broader understanding of how these resources could be integrated into European medical practices. Its legacy endures as a foundational text in the history of American herbal medicine.​