Identifying Plants: The Herbal Becomes the Flora

In 1622 Caspar Bauhin published Catalogus plantarum circa Basileam sponte nascentium (Catalog of plants occurring naturally around Basel). This slim book was a list of the plants growing around Basel. It contained no illustrations, but it listed all the synonyms for the plants it described and details of where each plant might be found, and alternate pages were left blank for students to make their own notes. The catalog was intended for the use of medical students, but it was not a herbal in the traditional sense. It was possibly the first flora—a description of all the plants, useful or not, growing in a specified area.

Botany was still being taught as a branch of medicine, and physicians would continue to study plants until the expansion of the pharmaceutical industry displaced herbalism from the center of medical practice, but botanists were beginning to devote increasing amounts of time to the study of plants in general. Bauhin was a professor of anatomy as well as botany, and his catalog, written late in his career, was based on many years of field excursions. In it he drew attention to medicinal plants, but he did not confine himself to them. He described plants of all kinds. Bauhin's most important work was his Pinax theatri botanici, published in 1623, but in 1620 he had published a shorter introductory work, Prodromus theatri botanici (Introduction to botanical exposition), in which he included descriptions of 600 plants that no one before him had described, possibly because they had no known medical uses.

Other floras followed in subsequent years. These were local, describing the plants growing close to where the author lived. In 1659 John Ray published his Cambridge Catalog, describing the plants growing around Cambridge. Plantae Coldenhamiae by the Scots-born physician, farmer, botanist, and four-time governor of New York Cadwallader Colden (1688–1776), published in 1743 with a revised edition in 1751, was possibly the first American local flora. Colden's flora described the plants on his Coldenham Estate near Newburgh, New York. Linnaeus published Colden's work in Uppsala and spoke highly of it.

European explorers were also compiling floras of other continents. One of the most notable of these was the Polish botanist and Jesuit missionary Michal Piotr Boym (ca. 1612–59). In 1643 Boym set out on a journey to eastern Asia and described the plants, animals, peoples, and customs of all the lands he visited along the way. He wrote a description of the flora and fauna of Mozambique that reached Rome but was never published. His Chinese flora, on the other hand, was published in Vienna in 1656. Boym illustrated his Flora Sinensis in color with annotations in Latin and Chinese (with guides to pronunciation) and, despite the title, he included animals—for some reason including a hippopotamus!—as well as plants. It was a small work, describing only 21 plants and eight animals and with a total of 23 pictures, but it is the earliest book about the plants of subtropical China written by a European.